# Infrared - sunlight vs. basking lamps



## lilacdragon

Hi, guys.
In a long discussion in another thread, ( http://www.tortoiseforum.org/thread-83263.html ) on the causes of pyramiding, the subject of basking lamps came up. A question was raised about my comment that short-wavelength infrared was vital for basking, but there were additional concerns with artificial lamps vs natural sunlight. As the discussion on that thread has continued into nutritional concerns, I'm posting about infrared separately, here. 

The infrared story is very interesting. It is something I only started looking at in the last year or two and it all ties in really well with the UVB story, and it is quite theoretical. Basically, it is to do with the interaction of sunlight and water.

"Sunlight" is arbitrarily sub-divided by scientists into UV, Visible, and Infrared wavelengths.
Infrared is subdivided by scientists into infrared-A (IR-A, 780â€“1400 nm) and infrared-B (IR-B, 1400â€“3000 nm) and infrared-C (IR-C, 3000 nmâ€“1 mm).

The infrared wavelengths of sunlight are almost all in the shorter wavelengths called IR-A. There is a small amount of IR-B but no IR-C.
IR-A wavelengths are very close to red light, and indeed they work very much like red light; they can go through the skin and penetrate deep into the body. Think how, if you shine a bright torch against the back of your hand in a dark room, you can see the red light coming through your palm. IR-A will gently warm through the entire body of a small reptile as it basks. Bigger ones will of course take a lot longer to warm up. 
There is something special about the IR-A from sunlight, though, that needs mentioning.
Our earth's atmosphere contains a great deal of moisture - water vapour and droplets - in the miles of atmospheric gas filtering the light from the sun. Water absorbs very specific wavelengths of the sun's radiation. When it absorbs this energy, it warms up. The wavelengths in the IR-A region that are absorbed by water can be detected very easily by looking at a spectrum of sunlight, in the IR-A region. Where the water has absorbed the IR-A, it is in effect "used up", and so is missing from the spectrum; so you can see a big dip in the irradiance at this point. Here is a solar spectrum as it is in outer space (the yellow blocked-in part) and how it is on the earth's surface (the red blocked-in part) and you can see the big dips taken out of it by atmospheric water vapour, which are labelled (Hâ‚‚O):






(Image created by Robert A. Rohde / Global Warming Art
http://www.globalwarmingart.com/wiki/File:Solar_Spectrum_png)

I'll explain why this is important later on.

But the sun also warms the substrate, rocks, trees etc. Objects warmed by the sun re-radiate this heat in the longer wavelengths (IR-B and IR-C) that are also invisible, but can often be felt - hold your hand just above a hot sun-warmed rock and you will feel the long-wavelength heat as a prickly warmth on your skin. This long-wavelength infrared doesn't go deep. It hits the surface of the skin and immediately gives up its heat energy to the skin surface. It will warm the surface very fast, but the heat will need to warm deeper layers by conduction, a much slower process.

Indoors, we create IR-A with basking lamps (incandescent light bulbs, halogen bulbs, mercury vapour lamps and metal halides). Heat sources that do not also give off light, such as ceramic heaters, heat plates, and heat mats emit mainly longer wavelengths - IR-B and IR-C.

So it makes sense to use non-light-emitting heat sources for warming the air and the background environment, in the way that warm air and warm soil throws back heat after the sun has been on it all day.... In cooler northern climates, we typically place these to provide suitable ambient temperatures in areas that the tortoise will move around in when not basking.
And then we use basking lamps emitting visible light and IR-A when we are providing "sunlight" for basking species, and it makes sense to hang these lamps above the tortoise, like the sun.

But now we have to consider the difference between the infrared from a basking lamp and the infrared from natural sunlight.

This graph shows the spectrum of a halogen lamp (in red), so that you can compare it with the solar spectrum (in green). 





from: http://3dprinter.wikidot.com/dlp-projectors-optics

You'll notice that the halogen lamp doesn't have the big dips in its spectrum, caused by several miles of water vapour and droplets taking out the energy from those wavelengths. The halogen lamp also has a lot more IR-B than sunlight, and it also has some IR-C. So when the tortoise basks under a basking lamp, he gets ALL the IR-A wavelengths, including the wavelengths that are missing from the sunlight, plus some IR-B and IR-C.

But the IR-A wavelengths missing from sunlight are the wavelengths that are most readily absorbed by water molecules. Since the lamp is at most, 1-2ft above the tortoise, not several miles away, there cannot ever be enough atmospheric water vapour between him and the lamp to absorb those wavelengths. So where are the first water molecules those wavelengths encounter? ... inside the cells of the tortoise's carapace and skin! These immediately absorb the energy from those wavelengths of IR-A... creating heat in the carapace and skin.

The other IR-A wavelengths penetrate deeper and release their warming energy through all the body tissues, but these "dump" all their energy into the water inside the very top layers of skin and keratin.... 
And so do the IR-B and IR-C wavelengths. 
This sounds like it might well be a problem for parts of the body evolved to receive mainly sunlight, which has little or none of these wavelengths present...
I would love to know whether it is an important factor in pyramiding....

There is a growing use of red and infrared light in healing of wounds and stimulating the body's repair after injury, in human and veterinary medicine. Red lasers are mainly used, but a new technique using "water-filtered IR-A" is being pioneered by some German people and it looks very promising. 
For example: "Water-filtered infrared-A (wIRA) in acute and chronic wounds"
The idea is to have a thin layer of water in a special tray inside the lamp unit. It is terribly expensive and totally impractical for us as keepers, but it does look interesting. Here is something I just found on Wikipedia, showing a spectrum of "water-filtered IR-A" - see how the water is removing quite a large amount of those "water" wavelengths from the halogen lamp spectrum, and how there are other filters which remove the longer-wavelength IR-B and IR-C, too.





From: http://commons.wikimedia.org/wiki/File:WIRA-Wiki-GH-017E-en-Spectra-wIRA-sun-halogen-radiators.png
By Helmut Piazena (Helmut Piazena) [CC-BY-SA-3.0-de (http://creativecommons.org/licenses/by-sa/3.0/de/deed.en) ], via Wikimedia Commons.

So what do we, as reptile-keepers, do?
We have no alternative but to use some form of basking lamps and heaters, if we choose to keep ectotherms far from their natural habitats, in climates where they cannot survive outdoors. And if we use them carefully, combinations of incandescent lamps, halides, mercury vapour lamps, fluorescent tubes and even ceramic heaters have proven their worth over decades of successful reptile-keeping. But now we are becoming aware of the inevitable risks that our artificial heat and light sources carry with them.... I don't think there is cause for alarm, or drastic measures. But I'm sure there are things we can do to reduce the risks of too-intense localised heating - which is what seems to be the main issue here.

First, look at Testudoresearch's work with thermal imaging cameras.
Here's the forum post summarising it: http://www.tortoiseforum.org/thread-83263-post-787129.html#pid787129
Any tortoise with cold head and legs (blue in the first picture) is going to hang around longer under a heat source until his whole body is warm. If the heat source is a small circle - a "basking spot" - close under a small halogen lamp (as sold by SO many reptile stores as a "basking lamp") then only the top of the carapace is being heated, possibly quite severely overheated and dried out at the same time, as these images suggest. And how long will he have to stand there, cooking his carapace, to get his core temperature up to the right level...? 
So the first very positive step is for every basking "spot" to be converted into a basking "zone", with all sunlight wavelengths (heat, light and UV) covering, as evenly as possible, an area AT LEAST as large as the WHOLE tortoise with his legs and head fully extended. They will happily bask like that, given a big enough zone.... 
And to obtain this big zone, keepers will almost certainly need to take the second very positive step - moving the lamps further away from the tortoise, and changing all "spot" bulbs to "flood" bulbs. This will spread the beam of heat and light over a wider area. Often, with larger tortoises, it is best to arrange two, three or even more bulbs to cover a large enough area. I've seen this done very effectively in some zoos, using a combination of PAR38 flood halogen or tungsten incandescent bulbs and UV-emitting lamps. 
This of course requires the tortoises to be kept in suitably large enclosures or tortoise tables to allow a big basking zone and a big cooler area with a gradient between, and hides/ shelters. In my experience, it is extremely difficult if not impossible to achieve anything satisfactory in anything smaller than 4ft long....

Well... I guess that's my "take" on infrared lighting, to date.... I know I have a lot more to learn, and I'm sure others will chip in with their experiences and practical suggestions...? I am trialling the use of rectangular, outdoor floodlamps which have long thin so-called "linear halogen" R7s bulbs; in the UK these are widely used to light backyards and the sides of houses. They create much wider basking zones than "round" light bulbs. But they seem almost unknown in the States and in other European countries... PAR38 floods seem the next best thing.
And metal halides may be very well worth researching. They have far less IR-B and IR-C than incandescent bulbs and halogens... and a lot better quality visible light, too. 

Frances Baines
www.uvguide.co.uk


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## BeeBee*BeeLeaves

Excellent read to start the weekend, thank you so much lilacdragon. Thought provoking, great considerations! : )


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## Yellow Turtle

This is a great article. Thank you for taking the time to share this here.


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## Team Gomberg

I enjoyed reading this. Learning about IR-A is new to me. 
I am so glad to live in sunny SoCal where my torts can be outside either full time or close to it.
Only the leopard hatchlings are raised indoors and the high humidity must be helping to counter act the drying effect of the basking spot. 
There is still so much to learn and understand.


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## Testudoresearch

lilacdragon said:


> The infrared wavelengths of sunlight are almost all in the shorter wavelengths called IR-A. There is a small amount of IR-B but no IR-C.
> IR-A wavelengths are very close to red light, and indeed they work very much like red light; they can go through the skin and penetrate deep into the body. Think how, if you shine a bright torch against the back of your hand in a dark room, you can see the red light coming through your palm. IR-A will gently warm through the entire body of a small reptile as it basks. Bigger ones will of course take a lot longer to warm up.



Here's a real-life example. From today, 22 December. It has been very warm here, and for the first time since late September, I saw two tortoises emerge to bask.

Ambient temperature at 11.00 am 15.9C, RH 41.8%






Subsurface temperature at 50mm (2 inches). 8.00 C






Ambient temperature and RH at ground level






Carapace temperature






Plastron temperature






The heat in the body is very, very even. Top to bottom (literally). There are 'hot spots' as seen under most artificial 'basking lamps', and although I did not take a cloacal temperature here - on previous occasions I have, and I would confidently expect it to be +/- 1.5C of the external measurements.

Also note that RH is in the 42% max range.

There has been no rain to prompt this (and others remain down), so I suspect these two just felt it was warm enough to come out enjoy the sun for a few hours! Based on previous data, they are easily able to raise their body (including core) temperatures up to 12C or so above ambient by using various basking strategies.


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## lilacdragon

Beautiful!
Tiny solar panels.


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## Testudoresearch

Testudoresearch said:


> The heat in the body is very, very even. Top to bottom (literally). There are 'hot spots' as seen under most artificial 'basking lamps', and although I did not take a cloacal temperature here - on previous occasions I have, and I would confidently expect it to be +/- 1.5C of the external measurements.



TYPO Alert! That should of course read "There are *NO* hot spots".


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## keepergale

Good stuff here. I have just started using radiant heat panels for my tortoises. My impression is it suits them very well. They seem to bask as if they are outside. Still no substitute for the sun.
Does anyone know what "wave length" these heat panels utilize?


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## nearpass

keepergale said:


> Good stuff here. I have just started using radiant heat panels for my tortoises. My impression is it suits them very well. They seem to bask as if they are outside. Still no substitute for the sun.
> Does anyone know what "wave length" these heat panels utilize?



I would be curious what type of panels you use, and how you set them up?


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## lilacdragon

Hi, Keepergale.



> Does anyone know what "wave length" these heat panels utilize?


No, but I'd like to find out!
So I've just sent an email to one company (http://www.reptilebasics.com/rbi-radiant-heat-panels ) and asked them if they have a spectrum they can show me.

Frances


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## Testudoresearch

I have a 400w panel here that we will be running some IR Thermography tests on soon. Quite a lot of these are manufactured as "process" or "industrial control" heaters and frequently state they are excellent for "moisture removal" - which is not exactly what we are looking for with reptiles! So while the heat distribution may be superior to a concentrated spot source, the spectrum is of major concern (and they don't seem to publish much on what that really is).


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## keepergale

nearpass said:


> keepergale said:
> 
> 
> 
> Good stuff here. I have just started using radiant heat panels for my tortoises. My impression is it suits them very well. They seem to bask as if they are outside. Still no substitute for the sun.
> Does anyone know what "wave length" these heat panels utilize?
> 
> 
> 
> 
> I would be curious what type of panels you use, and how you set them up?
Click to expand...

I am using a repurposed "Boaphile" cage with their 1611 Radiant heat panel mounted 12 inches above the floor. Its only a 40 watt unit and produces idea temperatures in my reptile room. The cage holds humidity well with it running 24/7. It heats a broad area of the cage but does not seem quite so intense as the CHE's.


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## Testudoresearch

The core question is:

What is their effect on water molecules in close proximity? If the wavelengths they emit are in the range that is very well absorbed by those molecules, you will get surface (skin) heating with not-so-great deeper penetration... one consequence of that (if it is the case) is that there is an increased risk of tissue damage (burns), and dehydration. .... so knowing what wavelengths are being emitted is critical to being able to predict their effect on living organisms.

Look closely. This is one of our research images that shows an effect from IR-A at close range. What is happening here? See the straight lines in a kind of 'quilt' pattern? Those are the 'sutures' between the plates. These are very rich in blood vessels... hence... water molecules! You can see here how they are getting hotter than the surrounding tissue....they are disproportionally absorbing IR....






You do not see anything like as extreme an effect as this under natural sunlight. It is one of those 'unseen' consequences that can happen when using very artificial methods of husbandry. I too have been using (and recommending) heat lamps for years with realizing anything like this was happening..... when I first started looking at basking tortoises and turtles with an infra-red imaging system, I was absolutely shocked at what I was seeing. I checked the literature - surely this must be known? Understood? Explained somewhere? Nope. Nothing. So... this is all a fairly recent set of discoveries. We are learning more all the time. I did not begin to understand initially what was _causing_ this.... until I consulted with Frances, who has made extensive investigations into the UV and IR spectra and their effects on reptiles. Only then did it start to "click".... IR-A... water-filtered sunlight... lamp wavelengths...effects on water molecules...

We have an ultra-high resolution IR imaging system arriving in the New Year, so should be able to get even more data on this phenomenon in the near future. This has incredibly wide significance for reptile keepers generally. Not just tortoises. Iguanas... snakes... everything.


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## ulkal

Apologies for responding so late,especially because this is in response to a question I posed. I did not see this thread and thought my question just disappeared from the radar. Thank you very much for the extensive and comprehensible answer.
So, IR-A is vital to warm up the tortoise, but not its full range. If I interpreted correctly, the lower end of the spectrum does get filtered out less. Would those be the wavelengths that penetrate deeper? And the longer wavelengths in the IR-A spectrum would not go so deep and therefore dry the carapace and skin? I know, I probably oversimplified it, as you cannot bring it down to shorter-wavelength IR-A gets through, the longer-Wavelength IR-A doesn't. 
Would running a humidifier, for example, have any effect on filtering out the IRA or would the filtering effect of ambient humidity be so shortlived that it did not matter (I think Testudoresearch showed the diagram of the decrease in RH when running a MVB)


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## Testudoresearch

ulkal said:


> Would running a humidifier, for example, have any effect on filtering out the IRA or would the filtering effect of ambient humidity be so shortlived that it did not matter (I think Testudoresearch showed the diagram of the decrease in RH when running a MVB)



Unfortunately, the amount of water vapor in air between a lamp and a basking reptile as would be generated by a humidifier is so limited it would have no effect at all. It takes many, many Km of water vapor to filter these wavelengths as they pass through the atmosphere, for example. There are such things as water-filtered IR-A (wIRA) lamps (designed for medical use). These employ a liquid-filled filter, sometimes with external cooling systems. This is an example.

They are unfortunately extremely expensive and not practical for routine reptile use, with very high running costs in addition to the purchase price, which is many thousands each....

It would be great if a simple, practical solution existed at an affordable price, but right now, it seems it does not.


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## mikeh

What about convection heat. Convection ovens are known to cook meats faster and evenly thru out, convection heat "drives" the heat deep into the core without burning the outside. 

I have been using this type of heat since I gave up basking bulbs few months back after reading posts about basking lights and their effects on chameleon forum, same as we are discussing here. 

While I don't know yet if I am depriving the animal by not providing IRA created by basking bulb, I will say the animal warms up evenly top/bottom, front and back, basks as it would with basking light and acts normal. 

In a closed enclosure I sneaked 100W cable across side and back walls (picture flat coil), and use low voltage fan to drive the heat around the enclosure. (T5HO lights provide some additional heat). This forced air circulation drives the heat into the tortoise and substrate as well. Its a slower process, takes about an hour to raise the temp from 75F to 85F and another half hour to 90F. When I check on tortoise tortoise 2 hours after lights on, it indeed is evenly warm to the touch, so is all the substrate. I alternate days between 85F, 90F, 80F,with some spikes of 93F. At 94F and above the tort always retreats into the hide after spending half hour or so at this temperature. Therefore I don't see the need to go much higher above 91-92F. 

This type of heat transfer also happens in nature and seems very efficient, think wind. For example, at ambient temp of 85F at ground level, with the forced air circulation (convection heat) the substrate gets warm in reasonably short time. Without the air circulating the substrate never gets warm and stays cool all day. I will get a temp gun to measure this difference, but it is very noticeable just by using hand. 

Question is though, am I depriving the animal of something beneficial by using this type of a heat for it to reach its operating temperatures, that I am not sure of. It still warms up evenly including its core to operating and basking temperatures just by different method.


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## Team Gomberg

Mikeh, I'm very curious to learn more about what you do.
I'll message you for details so I don't detail this thread...


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## lilacdragon

Mikeh, are you saying that the air throughout your entire enclosure is reaching 85 - 90F/ 30 - 35C ?
This is very strange - how do you achieve a temperature gradient? What is the air temperature in their hide?
If you are using buried heat cable then it will be heating the walls by conduction, and the hot walls will in turn warm the air by conduction, and also warm objects nearby by radiating long-wavelength IR-C. I agree that this completely removes the problem we're discussing regarding IR-A... but I'm not sure about the "forced air circulation drives the heat into the tortoise" ... this seems very un-natural. 
What is the humidity like, and how do you control it? I would have expected a flow of warm air to have a desiccating effect.
I was driving north out of Adelaide in October 2006, and there was an "extreme weather" situation, with air temperatures rising to 35 - 40C and a stiff wind. I've never encountered anything like it - getting out of the car, it felt like someone had aimed a gigantic hairdryer at us. Later we learned that every field of uncut barley across the entire section of South Australia had been dessicated by that wind and the whole vast crop, wind-dried and useless, had to be ploughed back under. We saw not a single wild animal or bird, the entire day.

My main concern with this concept is that although warming the whole environment is a good way of creating a habitat for thermo-conformers - non-basking species - it seems un-natural for basking species. Basking species in the wild don't rely upon ambient (air) temperature to achieve their desired core temperature - they typically absorb radiation, a bit like solar panels, until their core temperature is well in excess of the air temperature. So they can be fully active with proper core temperatures throughout the day, when the air temperature is only in the mid twenties C. 

Is it okay for them to have to wait until the whole "heated" part of their enclosure has warmed up, along with their bodies, before they can achieve the correct core temperature?

How bright is your illumination, now you have only the UV lighting? I'd have thought it might be rather gloomy..? 
What about some metal halides for bright light with a lot less infrared?

Frances


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## mikeh

*Re: RE: Infrared - sunlight vs. basking lamps*



lilacdragon said:


> Mikeh, are you saying that the air throughout your entire enclosure is reaching 85 - 90F/ 30 - 35C ?
> This is very strange - how do you achieve a temperature gradient? What is the air temperature in their hide?
> If you are using buried heat cable then it will be heating the walls by conduction, and the hot walls will in turn warm the air by conduction, and also warm objects nearby by radiating long-wavelength IR-C. I agree that this completely removes the problem we're discussing regarding IR-A... but I'm not sure about the "forced air circulation drives the heat into the tortoise" ... this seems very un-natural.
> What is the humidity like, and how do you control it? I would have expected a flow of warm air to have a desiccating effect.
> I was driving north out of Adelaide in October 2006, and there was an "extreme weather" situation, with air temperatures rising to 35 - 40C and a stiff wind. I've never encountered anything like it - getting out of the car, it felt like someone had aimed a gigantic hairdryer at us. Later we learned that every field of uncut barley across the entire section of South Australia had been dessicated by that wind and the whole vast crop, wind-dried and useless, had to be ploughed back under. We saw not a single wild animal or bird, the entire day.
> 
> My main concern with this concept is that although warming the whole environment is a good way of creating a habitat for thermo-conformers - non-basking species - it seems un-natural for basking species. Basking species in the wild don't rely upon ambient (air) temperature to achieve their desired core temperature - they typically absorb radiation, a bit like solar panels, until their core temperature is well in excess of the air temperature. So they can be fully active with proper core temperatures throughout the day, when the air temperature is only in the mid twenties C.
> 
> Is it okay for them to have to wait until the whole "heated" part of their enclosure has warmed up, along with their bodies, before they can achieve the correct core temperature?
> 
> How bright is your illumination, now you have only the UV lighting? I'd have thought it might be rather gloomy..?
> What about some metal halides for bright light with a lot less infrared?
> 
> Frances



These are the same questions I ask my self. Yes, this concept seems unnatural given how arid species achieve their operating temperature in nature. But isn't the final effect the same if the tortoise reaches the same operating temperatures?...I wonder.

As for having to wait, to reach operating temperature? I have observed, at least the tortoise here,(New Jersey) in the summer housed outside ( now 8month old GPP) to be active in the early mornings, hours before the sun is up for basking, to be grazing and walking around even in 70F. Basking would occur after during morning hours, avoiding sun during midday hours and basking and grazing again late afternoon. This to me seems tortoise doesn't necessarily need basking to warm up first thing upon awakening to function. I could be wrong. 

The heat cables in the closed chamber are not burried. They run across 2 side walls of the enclosure well above tortoise level. The fan runs diagonally next to the cables driving the heat from the cables and gently circulating the air, by no means stiff wind conditions, rather gentle breeze. The substrate is kept moist, misted in the evening, yielding night time humidity in the 90s, but daytime humidity in the 70-80%. Keeping humidity levels up is no issue at all. (After reading Andy's posts I am further reducing the humidity levels, especially day time). There are number of weeds growing inside the enclosure, doing well untill eaten. There is a dense vegetation in one corner surrounding the hide made of rocks, here the air movement is largely reduced. Temperature inside the hide is only 3-4F lower but with no air movement the effect is amplified. 

Lighting is done by double 48" T5HO specular aluminum reflector fixture with Arcadia 3D+ 12% tube and 3500k grow tube at 15-17" height. Very bright. This double fixture produces some radiant heat reaching the floor, the tortoise seems to recognize this. (A QUAD fixture could possibly be enough of single source for heat and UVB for smaller tortoises, as the heat ouptut by quad/4 bulb fixture is multiplied. I have inquired Andy about this for his upcoming tests for IRA spectrum, your input would be much appreciated, I have read your articles on Arcadia.)

I use digital readers for temp and humidity but will get a temp gun to take readings of tortoise itself. I base much of what I do with this idea on tortoises behavior. I have seen some distress with this set up at prolonged 94F where tortoise will retreat into the hide. But I have also seen this with heat bulbs. The tort would sit under the bulb until it would reach its upper tolerating temp limit then retreat into the hide, only to repeat this cycle of thermo regulating between hot and cool. At temps of 80-90F tortoise acts normal, active, alert, feeding amd basking. 
How about keeping the tort in the range of a sweet spot it is looking for in the first place. Lets say 5degree radiant. Is it necessary to create 100F-105F basking spot with 80F cool end? Perhaps yes if the basking bulb is also the only source of bringing up the ambient temp in the rest of the enclosure. Other wise won't a lower gradient aimed at the sweet spot serve equally without creating this very hot dry spot? 

You have valid concerns Frances, and I am not sure if this kind of a set up with convection heat is ok for arid species. I will do some tweaking and take measurements with heat gun. 
Mike


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## Testudoresearch

Interesting concept. While it undoubtedly removes one problem, I also have concerns it may be creating others. I have only done very limited testing with forced-air systems (back in 2009 when looking at vivaria and systems in stores and zoo exhibits), and have never looked at them in sufficient depth, but, unless very careful attention is paid to humidity control, there can indeed be quite serious "dehydrating" effects. If you do use humidification, at a level to overcome that, you enter another danger zone (familiar to HVAC engineers), of creating an environment where fungal organisms and diseases such as legionnaire's disease can thrive. With reptiles, there is the added dimension of removing key thermoregulation 'cues' and opportunities. Tortoises specifically are highly geared to using 'directional' heat from radiant sources, and balancing this with indirect, reflected sources from the ground, etc. They, like many lizards, have highly developed behavior patterns and basking postures designed to 'work' in this mode. If this is removed - you may get the body temperature to where you want it, but what else might be disrupted in the process? One thing I have learned over the years is that the further you remove things from how they are "supposed" to work, the more "invisible" problems you can end up creating.They can stay "invisible" for quite some time. Until things start to crash. 

Do not wish to put a damper on people thinking of inventive solutions. We need some solutions. But be careful.

You are quite right that tortoises can, in some circumstances, be active without direct solar heat. Examples include true nocturnal activity in Testudo graeca and Geochelone sulcta... feeding by moonlight... not common, but it certainly happens. We have recorded it numerous times now in Testudo, and the late M. R. K. Lambert recorded it in Mali with G. sulcata.


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## lilacdragon

Hi, MikeH



> Lighting is done by double 48" T5HO specular aluminum reflector fixture with Arcadia 3D+ 12% tube and 3500k grow tube at 15-17" height. Very bright. This double fixture produces some radiant heat reaching the floor, the tortoise seems to recognize this. (A QUAD fixture could possibly be enough of single source for heat and UVB for smaller tortoises, as the heat ouptut by quad/4 bulb fixture is multiplied.



That sounds a very nice fixture....
I don't suppose you're in the UK, anywhere near London? If you visit ZSL London Zoo, and go to the Galapagos Tortoise House you'll see what they've just installed in there - a massive array of _four_ 4ft long Arcadia "SuperZoo" T5-HO units, each with six 54-watt Arcadia T5 D3+ 12%UVB tubes. These 4 units are suspended from the ceiling in two pairs, about 7ft above the tortoises' backs, and create a huge zone of more or less uniform UVI 3 - 3.5 about 10 feet square. Between the two pairs is a huge ceramic heat panel, emitting long-wavelength infrared; but this is a temporary fixture to boost the warmth under the array, because they are about to replace it with a row of halogen heaters.
The visible light is excellent and the tortoises seemed to be treating it as a "patch of sunlight".... The most impressive thing is the sheer size of the basking zone, enabling up to five adult Galapagos tortoises to sprawl out underneath it. When I was there, two were doing just that, with their legs and necks extended. So good to see...

If you have got your UV levels where you want them, with a single D3+ paired with a non-UVB T5 tube for visible light, you could certainly add a second pair of tubes - both non-UVB - to boost the visible light. Or you could use your quad fixture with two D3+ and two non-UVB tubes, raised up higher to achieve the same UVB level but covering a larger area. 
Or for a better visible spectrum still, you could install a high-quality, non-UVB metal halide lamp - either a PAR38 externally-ballasted bulb, or a linear metal halide in a flood lamp fixture - at a greater distance, to cover the same basking area with a much brighter light with UVA and visible wavelengths, but not nearly as much infrared as a basking lamp. (Check out the spectrum of the Iwasaki EYE Color Arc halide in my first post on this thread).

Best wishes,
Frances


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## mikeh

Frances, I live in the northeast US, but can picture the array of lights at the Zoo you describe, as I have seen those and massive 8tube fixtures. 
Metal halide sounds ideal, but now we are getting into territory of high expense and more complicated set ups. Personally I will consider it.

The idea though is to try to come up with a system to keep it simple and price reasonable enough for the average tortoise keeper. The average indoor set consists of an MVB and CHE, or basking light, florescent uvb and CHE, or something in between. All creating a hot dry spots with the exception of florescent UVB. Most people here are using T8 lights and are just learning about about T5HO. 

I think a quad or higher T5HO fixture weather it be 24" or 48", enclosure size appropriate, at usable height distance can create an even large gentle basking area and could possibly replace hot heat lights in many set ups. 24" quad fixture is rated at around 108watt output. Of this a significant amount is transformed into heat (unlike that of T8) inside the bulb and projected downward, with help of reflectors. 

I have a 6'x3'x12" open table not in use. Tomorrow, I will set it up with 4' quad fixture at different usable heights and take pictures of temperature along with humidity under the lights and against the background ambient.


----------



## mikeh

Test results.

Objective: Determine viability of multi tube T5HO fixture for single source of UVB/basking/heating all in one, in an open table enclosure and its effects on relative humidity under the fixtures tubes.

Temperature and humidity data was collected to determine fixtures heat output against ambient room temperature and humidity of the room, and fixtures ability to efficiently heat up test objects.

Set up: All materials were left in the temperature stabilized room for 3 hours prior to testing, excluding the tortoise. Fixture was set up 14" above the middle of the 6'x3' open table. Two large flat slate stones were placed under the fixture. Few plants were placed in the enclosure. No substrate was used. Ambient temperature and RH of the room were constantly monitored with dual digital reader. Surface temperature of each test object was recorded prior to start of the test including slate rocks, infrared temp gun was used. Detailed photos were taken thru out the test.

The fixture was initially turned on and left on for one hour before testing. At the end of the hour ambient temperature and RH under the fixture were recorded. Surface temperature of the slate rocks were recorded.

Test objects were then placed on top of the slate rocks under the fixture. Surface temperature of each of the test objects was recorder at 30 minutes and again at 60 minutes after initial placement. After 60 minutes all test objects were cut in half to record their core temperature. Temperature of the bottom of objects was also recorded.

Test objects: 
a) live 3.25" leopard tortoise, hoping it will cooperate to bask, if not zip ties are on hand to strap it down.
b) raw 3.5" sweet potato
c) raw 5.25" acorn squash
d) 4" stack of 4x4 limestone tiles.

Materials specifications: 

Table: 6'x3'x12" constructed of pine boards.
Fixture: New Wave quad (4tube) 48" T5HO equipped with specular aluminum reflectors. Total output: 216watts, 2Amps
Light bulbs: one T5HO Zoomed 5% UVB and three T5HO 5600K grow lights. 
Fixture measurements: 48"x11"x3" (ballasted at the top with louvers for cooling.)


MEASURED AND RECORDED DATA:

Ambient room temp thru out the test:
74F
Room RH thru out the test: 
39-42%


Ambient temp under the fixture, 1" above the slate rock at 60 mins after turned on: 90-91F

Slate rock surface temp at 60 mins: 92-94F

RH under the fixture at 60 mins: 24-28%

Ambient temp and RH remained constant after 60mins.

SWEET POTATO data:
Surface temp prior to test: 69.8F
Top @30 mins: 81.4F
Top @60 mins: 87.5F
Core (cut in half) @ 60 mins:82F
Bottom @60 mins:82F

ACORN SQUASH data:
Surface temp prior to test: 69F
Top @30mins: 82F
Top @60mins: 89.1F
Core (cut in half) @ 60 mins: 77F**
Bottom @60 mins: 79.2F

4x4 TILES data:
Surface temp prior to test: 74F
Top @30mins: 84.5F
Top @60mins: 88F
Core (stack cut in half) 60mins: 86F
Bottom @60mins:84.1F

TORTOISE data: 
Surface temp prior to test: 79.5F
Top @30mins: 84F*
Top @60mins: 90.5F*
Core (cut in half) 60mins: Inconclusive, tortoise was unwilling to cooperate at this point.
Bottom @60mins: 87.7F

*Tortoise did not fully cooperate and had to be moved back under the fixture number of times. About 90% of the one hour was spent under the fixture. 


*Quick data facts:*
1) This type of a fixture at 14" height was able to maintain (directly under) a constant ambient temp of *15-17F higher* against the room temperature in an open table set up. 

2) Relative humidity under the light was *reduced by 12-15% *against the backround humidity and remained constant. 

3) In one hour the heat output was able to heat up 3.25" tortoise from 79.5F to 90.5-87.7F including its core in a 74F open floor room.

4) The fixture creates a large, very even and gentle basking area of 48"x11", somewhat replicating a patch of morning sun. It also raised temperature of its outer surroundings noticeably, surface temperature 7" from the outer edge of fixture was recorder at 85F.

I will upload detailed photos of the experiment and my conclusions shortly from my phone. Hope this will be helpful to some, any questions are welcome.


----------



## nearpass

mikeh said:


> Test results.
> 
> Objective: Determine viability of multi tube T5HO fixture for single source of UVB/basking/heating all in one, in an open table enclosure and its effects on relative humidity under the fixtures tubes.
> 
> Temperature and humidity data was collected to determine fixtures heat output against ambient room temperature and humidity of the room and fixtures ability to efficiently heat up test objects.
> 
> Set up: All materials were left in the temperature stabilized room for 3 hours prior to testing, excluding the tortoise. Fixture was set up 14" above the middle of the 6'x3' open table. Two large flat slate stones were placed under the fixture. Few plants were placed in the enclosure. No substrate was used. Ambient temperature and RH of the room were constantly monitored with dual digital reader. Surface temperature of each test object was recorded prior to start of the test including slate rocks, infrared temp gun was used. Detailed photos were taken thru out the test.
> 
> The fixture was initially turned on and left on for one hour before testing. At the end of the hour ambient temperature and RH under the fixture were recorded. Surface temperature of the slate rocks were recorded.
> 
> Test objects were then placed on top of the slate rocks under the fixture. Surface temperature of each of the test objects was recorder at 30 minutes and again at 60 minutes after initial placement. After 60 minutes all test objects were cut in half to record their core temperature. Temperature of the bottom of objects was also recorded.
> 
> Test objects:
> a) 3.25" leopard tortoise, hoping it will cooperate to bask, if not zip ties are on hand to strap it down.
> b) 3.5" sweet potato
> c) 5.25" acorn squash
> d) 4" stack of 4x4 limestone tiles.
> 
> Materials specifications:
> 
> Table: 6'x3'x12" constructed of pine boards.
> Fixture: New Wave quad (4tube) 48" T5HO equipped with specular aluminum reflectors. Total output: 216watts, 2Amps
> Light bulbs: one T5HO Zoomed 5% UVB and three T5HO 5600K grow lights.
> Fixture measurements: 48"x11"x3" (ballasted at the top with louvers for cooling.)
> 
> 
> Measured recorder data:
> 
> Ambient room temp thru out the test:
> 74F
> Room RH thru out the test:
> 39-42%
> 
> 
> Ambient temp under the fixture 1" above the slate rock at 60 mins after turned on: 90-91F
> 
> Slate rock surface temp at 60 mins: 92-94F
> 
> RH under the fixture at 60 mins: 24-28%
> 
> Ambient temp and RH remained constant after 60mins.
> 
> SWEET POTATO data:
> Surface temp prior to test: 69.8F
> Top @30 mins: 81.4F
> Top @60 mins: 87.5F
> Core (cut in half) @ 60 mins:82F
> Bottom @60 mins:82F
> 
> ACORN SQUASH data:
> Surface temp prior to test: 69F
> Top @30mins: 82F
> Top @60mins: 89.1F
> Core (cut in half) @ 60 mins: 77F**
> Bottom @60 mins: 79.2F
> 
> 4x4 TILES data:
> Surface temp prior to test: 74F
> Top @30mins: 84.5F
> Top @60mins: 88F
> Core (stack cut in half) 60mins: 86F
> Bottom @60mins:84.1F
> 
> TORTOISE data:
> Surface temp prior to test: 79.5F
> Top @30mins: 84F*
> Top @60mins: 90.5F*
> Core (cut in half) 60mins: Inconclusive, tortoise was unwilling to cooperate at this point.
> Bottom @60mins: 87.7F
> 
> *Tortoise did not fully cooperate and had to be moved back under the fixture number of times. About 90% of the one hour was spent under the fixture.
> 
> 
> *Quick data facts:*
> 1) This type of a fixture at 14" height was able to maintain (directly under) a constant ambient temp of *15-17F higher* against the room temperature in an open table set up.
> 
> 2) Relative humidity under the light was *reduced by 12-15% *against the backround humidity and remained constant.
> 
> 3) In one hour the heat output was able to heat up 3.25" tortoise from 79.5F to 90.5-87.7F including its core in a 74F open floor room.
> 
> 4) The fixture creates a large, very even and gentle basking area of 48"x11", somewhat replicating a patch of morning sun. It also raised temperature of its outer surroundings noticeably, surface temperature 7" from the outer edge of fixture was recorder at 85F.
> 
> Hope some have found this useful. Any questions are welcome. I will upload detailed photos of the experiment and my conclusions shortly from my phone.



Now that's really impressive! Am looking forward to the pictures!


----------



## mikeh

*Re: RE: Infrared - sunlight vs. basking lamps*



mikeh said:


> Test results.
> 
> Objective: Determine viability of multi tube T5HO fixture for single source of UVB/basking/heating all in one, in an open table enclosure and its effects on relative humidity under the fixtures tubes.
> 
> Temperature and humidity data was collected to determine fixtures heat output against ambient room temperature and humidity of the room, and fixtures ability to efficiently heat up test objects.
> 
> Set up: All materials were left in the temperature stabilized room for 3 hours prior to testing, excluding the tortoise. Fixture was set up 14" above the middle of the 6'x3' open table. Two large flat slate stones were placed under the fixture. Few plants were placed in the enclosure. No substrate was used. Ambient temperature and RH of the room were constantly monitored with dual digital reader. Surface temperature of each test object was recorded prior to start of the test including slate rocks, infrared temp gun was used. Detailed photos were taken thru out the test.
> 
> The fixture was initially turned on and left on for one hour before testing. At the end of the hour ambient temperature and RH under the fixture were recorded. Surface temperature of the slate rocks were recorded.
> 
> Test objects were then placed on top of the slate rocks under the fixture. Surface temperature of each of the test objects was recorder at 30 minutes and again at 60 minutes after initial placement. After 60 minutes all test objects were cut in half to record their core temperature. Temperature of the bottom of objects was also recorded.
> 
> Test objects:
> a) live 3.25" leopard tortoise, hoping it will cooperate to bask, if not zip ties are on hand to strap it down.
> b) raw 3.5" sweet potato
> c) raw 5.25" acorn squash
> d) 4" stack of 4x4 limestone tiles.
> 
> Materials specifications:
> 
> Table: 6'x3'x12" constructed of pine boards.
> Fixture: New Wave quad (4tube) 48" T5HO equipped with specular aluminum reflectors. Total output: 216watts, 2Amps
> Light bulbs: one T5HO Zoomed 5% UVB and three T5HO 5600K grow lights.
> Fixture measurements: 48"x11"x3" (ballasted at the top with louvers for cooling.)
> 
> 
> MEASURED AND RECORDED DATA:
> 
> Ambient room temp thru out the test:
> 74F
> Room RH thru out the test:
> 39-42%
> 
> 
> Ambient temp under the fixture, 1" above the slate rock at 60 mins after turned on: 90-91F
> 
> Slate rock surface temp at 60 mins: 92-94F
> 
> RH under the fixture at 60 mins: 24-28%
> 
> Ambient temp and RH remained constant after 60mins.
> 
> SWEET POTATO data:
> Surface temp prior to test: 69.8F
> Top @30 mins: 81.4F
> Top @60 mins: 87.5F
> Core (cut in half) @ 60 mins:82F
> Bottom @60 mins:82F
> 
> ACORN SQUASH data:
> Surface temp prior to test: 69F
> Top @30mins: 82F
> Top @60mins: 89.1F
> Core (cut in half) @ 60 mins: 77F**
> Bottom @60 mins: 79.2F
> 
> 4x4 TILES data:
> Surface temp prior to test: 74F
> Top @30mins: 84.5F
> Top @60mins: 88F
> Core (stack cut in half) 60mins: 86F
> Bottom @60mins:84.1F
> 
> TORTOISE data:
> Surface temp prior to test: 79.5F
> Top @30mins: 84F*
> Top @60mins: 90.5F*
> Core (cut in half) 60mins: Inconclusive, tortoise was unwilling to cooperate at this point.
> Bottom @60mins: 87.7F
> 
> *Tortoise did not fully cooperate and had to be moved back under the fixture number of times. About 90% of the one hour was spent under the fixture.
> 
> 
> *Quick data facts:*
> 1) This type of a fixture at 14" height was able to maintain (directly under) a constant ambient temp of *15-17F higher* against the room temperature in an open table set up.
> 
> 2) Relative humidity under the light was *reduced by 12-15% *against the backround humidity and remained constant.
> 
> 3) In one hour the heat output was able to heat up 3.25" tortoise from 79.5F to 90.5-87.7F including its core in a 74F open floor room.
> 
> 4) The fixture creates a large, very even and gentle basking area of 48"x11", somewhat replicating a patch of morning sun. It also raised temperature of its outer surroundings noticeably, surface temperature 7" from the outer edge of fixture was recorder at 85F.
> 
> I will upload detailed photos of the experiment and my conclusions shortly from my phone. Hope this will be helpful to some, any questions are welcome.



Tested Fixture. 20,000 lumes output.




Test Set up





Ambient temp/humidity readings thru out the experiment. "Indoors" indicates room readings. "Outdoors" indicates readings under the fixture. The sensor for the fixture reading is the white rectangle on the slate rock with sensor facing up.





Readings of objects and enclosure right before start










Photos of random readings during the test.
Acorn Squash 





Potato





Tiles



Tortoise






Missed tortoise temp before testing.


----------



## nearpass

Will have to look this over much more in depth tomorrow when I'm not half asleep and snowed in, but this looks to cover the entire enclosure, at least, obviously, for your test. I think the concept is fantastic, but wonder about adapting it to a somewhat smaller enclosure, or, more accurately, to allow for thermo and light exposure choices. Do you think this can be accomplished with a somewhat smaller fixture over, say, half an enclosure?


----------



## mikeh

This will give you better perspective on enclosure 6x3 and fixture 4'x11" used in the test. 



In the very first image you can see thermometer placed in the far end of enclosure where the temp remained at 74F, due to the box blocking the heat. If the fixture was suspended my guess is the temperature in very far end would be 76-80F

Sure for 4x2 enclosure 24"quad fixture would work as well. Darker areas can be created with plants.


----------



## turtlesteve

Testudoresearch and others,

It should be possible to find or develop a solid filter that blocks the same IRA wavelengths that are absorbed by water. This could be used in front of an incandescent or halogen heat lamp. UV would then be provided by fluorescent lighting (such as the Arcadia bulbs) to avoid introducing un-filtered IR light.

I can help with finding the appropriate filter material if anyone is willing or interested in testing this approach.

Steve P.


----------



## lilacdragon

MikeH - this is a really great piece of research!
For species that don't need high basking temperatures (I guess that includes most tortoises?) this looks really worth pursuing!!
I'm not sure that one Reptisun 5.0 tube in a reflector at 14" distance is giving sufficient UVB. I'll need to dig out some charts and see what levels you're likely to be getting... But of course you've got the ability to swap around any of the 4 tubes into UV versions, and there are different "strengths" of UVB as well...

I too thought at first, like Nearpass, that it was covering the whole enclosure but MikeH's new photo makes it look ideal for a pen that size.

(I also got a shock when I first read about tying the tortoise down with cable ties!  ... then I read about cutting it in half, too, and I decided this must be a joke and I obviously have no sense of humour....  )

TurtleSteve - if you can develop a filter that absorbs only the wavelengths absorbed by water, I seriously think that you could not only have a big impact on reptile husbandry, but also make a lot of money on the patent, because have you seen the price of medical water-filtered IR-A units with their integral thin water panels?!!! (Not joking at all..) Go for it!
The only problem is that you need a spectrometer that can examine infrared wavelengths, to see if it works. Do you have access to one? (Mine only goes up to 800nm so is useless for IR testing, unfortunately.)


----------



## Saleama

mikeh said:


> Test results.
> 
> Objective: Determine viability of multi tube T5HO fixture for single source of UVB/basking/heating all in one, in an open table enclosure and its effects on relative humidity under the fixtures tubes.
> 
> Temperature and humidity data was collected to determine fixtures heat output against ambient room temperature and humidity of the room, and fixtures ability to efficiently heat up test objects.
> 
> Set up: All materials were left in the temperature stabilized room for 3 hours prior to testing, excluding the tortoise. Fixture was set up 14" above the middle of the 6'x3' open table. Two large flat slate stones were placed under the fixture. Few plants were placed in the enclosure. No substrate was used. Ambient temperature and RH of the room were constantly monitored with dual digital reader. Surface temperature of each test object was recorded prior to start of the test including slate rocks, infrared temp gun was used. Detailed photos were taken thru out the test.
> 
> The fixture was initially turned on and left on for one hour before testing. At the end of the hour ambient temperature and RH under the fixture were recorded. Surface temperature of the slate rocks were recorded.
> 
> Test objects were then placed on top of the slate rocks under the fixture. Surface temperature of each of the test objects was recorder at 30 minutes and again at 60 minutes after initial placement. After 60 minutes all test objects were cut in half to record their core temperature. Temperature of the bottom of objects was also recorded.
> 
> Test objects:
> a) live 3.25" leopard tortoise, hoping it will cooperate to bask, if not zip ties are on hand to strap it down.
> b) raw 3.5" sweet potato
> c) raw 5.25" acorn squash
> d) 4" stack of 4x4 limestone tiles.
> 
> Materials specifications:
> 
> Table: 6'x3'x12" constructed of pine boards.
> Fixture: New Wave quad (4tube) 48" T5HO equipped with specular aluminum reflectors. Total output: 216watts, 2Amps
> Light bulbs: one T5HO Zoomed 5% UVB and three T5HO 5600K grow lights.
> Fixture measurements: 48"x11"x3" (ballasted at the top with louvers for cooling.)
> 
> 
> MEASURED AND RECORDED DATA:
> 
> Ambient room temp thru out the test:
> 74F
> Room RH thru out the test:
> 39-42%
> 
> 
> Ambient temp under the fixture, 1" above the slate rock at 60 mins after turned on: 90-91F
> 
> Slate rock surface temp at 60 mins: 92-94F
> 
> RH under the fixture at 60 mins: 24-28%
> 
> Ambient temp and RH remained constant after 60mins.
> 
> SWEET POTATO data:
> Surface temp prior to test: 69.8F
> Top @30 mins: 81.4F
> Top @60 mins: 87.5F
> Core (cut in half) @ 60 mins:82F
> Bottom @60 mins:82F
> 
> ACORN SQUASH data:
> Surface temp prior to test: 69F
> Top @30mins: 82F
> Top @60mins: 89.1F
> Core (cut in half) @ 60 mins: 77F**
> Bottom @60 mins: 79.2F
> 
> 4x4 TILES data:
> Surface temp prior to test: 74F
> Top @30mins: 84.5F
> Top @60mins: 88F
> Core (stack cut in half) 60mins: 86F
> Bottom @60mins:84.1F
> 
> TORTOISE data:
> Surface temp prior to test: 79.5F
> Top @30mins: 84F*
> Top @60mins: 90.5F*
> Core (cut in half) 60mins: Inconclusive, tortoise was unwilling to cooperate at this point.
> Bottom @60mins: 87.7F
> 
> *Tortoise did not fully cooperate and had to be moved back under the fixture number of times. About 90% of the one hour was spent under the fixture.
> 
> 
> *Quick data facts:*
> 1) This type of a fixture at 14" height was able to maintain (directly under) a constant ambient temp of *15-17F higher* against the room temperature in an open table set up.
> 
> 2) Relative humidity under the light was *reduced by 12-15% *against the backround humidity and remained constant.
> 
> 3) In one hour the heat output was able to heat up 3.25" tortoise from 79.5F to 90.5-87.7F including its core in a 74F open floor room.
> 
> 4) The fixture creates a large, very even and gentle basking area of 48"x11", somewhat replicating a patch of morning sun. It also raised temperature of its outer surroundings noticeably, surface temperature 7" from the outer edge of fixture was recorder at 85F.
> 
> I will upload detailed photos of the experiment and my conclusions shortly from my phone. Hope this will be helpful to some, any questions are welcome.



All the great scientific data aside, I can't help but smile thinking about that cute little tort running away every time you tried to make him "sit" and "stay".


----------



## mikeh

*Re: RE: Infrared - sunlight vs. basking lamps*



lilacdragon said:


> MikeH - this is a really great piece of research!
> For species that don't need high basking temperatures (I guess that includes most tortoises?) this looks really worth pursuing!!
> I'm not sure that one Reptisun 5.0 tube in a reflector at 14" distance is giving sufficient UVB. I'll need to dig out some charts and see what levels you're likely to be getting... But of course you've got the ability to swap around any of the 4 tubes into UV versions, and there are different "strengths" of UVB as well...
> 
> I too thought at first, like Nearpass, that it was covering the whole enclosure but MikeH's new photo makes it look ideal for a pen that size.
> 
> (I also got a shock when I first read about tying the tortoise down with cable ties!  ... then I read about cutting it in half, too, and I decided this must be a joke and I obviously have no sense of humour....  )



Yes, well Frances that part of the experiment didn't exactly work out. When the tortoise seen the potato and squash being cut in half he bolted immediately. Unfortunately by the time I found him, his temperature has dropped considerably, thus going forward the data would render rather useless. 

Reptisun 5.0 had no real meaning to the test. It just happen to be on hand. Like you said bulbs can be swapped out in countless configurations to achieve any desired UVB output to match height that yields desires basking temperature without baking off the humidity. 

And that is whats so great about multi tube T5HO lights, versatility. (For example, If the fixture was at 12" height, it would have yielded basking temp higher still then in the test for those wanting 95F. Two Reptisun 5.0 or Arcadia D3 6% installed in the outer positions would create such a very nice large UVB area.) Higher temperatures still can be achieved with 6 and 8 tube fixtures. They don't have to 4' in length, 24" 6 or 8 tube fixture will create an area of even higher basking temperatures. 

I don't think any hatchling or smaller tortoise utilizes 100F direct midday sunlight for basking. So why are we creating these 100-110F hot spots with basking bulbs. Well, because thats what we know, to compensate with tiny basking spot, and to heat up the surrounding ambient temp with the same light. 

I think these multi tube T5HO lights can be used for basking and heating on any hatchling and smaller tortoises without much impact on humidity, creating milder but BIG and EVEN temp basking area.
That being said, I do not see these lights alone being efficient to heat up a 50lbs Sulcata, but neither will a 100-200watt basking bulb, baking top of the carapace. 

These multi tube T5HO lights appear to be very bright, but even at 20,000 lumes, it is still far cry from sunny day outside. Its just that indoor lighting is very dark and we are used to gloomy, dark enclosures. And For tropical spieces, no problem, plants, plants, plants, they love these lights. Create a nice plant canopy to break up the light and your tropical tortoise will bask under. Grass, clover, and weeds grow like crazy with these lights. After all these are grow lights.


----------



## Dizisdalife

I do like your sense of humor. Thanks for posting these results.


----------



## lilacdragon

This is very much how I see the use of a multi-T5 fixture set-up, too. I am very impressed by their possibilities.
I have a query about basking temperatures, though.
Are we talking about air temperatures or substrate temperatures?

I'm sure no self-respecting tortoise would be out basking in full sunlight at air temperatures of 100F, (38C) but in sunlight, at air temperatures as low as 48F (9C) I measured surface temperatures of 93F (34C) up in the Spanish Sierra Nevada, and that was the surface temperature of the backs of a group of basking wall lizards in the sunlit spot, too. There weren't any torts there (!) but a couple of days earlier at sea level we found a baby Testudo graeca at the edge of some grass clumps, and the air temperature was about 81F (27.6C), the substrate where he was standing was about 105F (40.6C) and his carapace temp was about 104F (40.2C)....

Obviously there are huge species differences in this, and I agree in principle that the main reason that people have in the past created these hot spots is because we haven't understood the need for wide basking zones. But I think also, until infrared non-contact thermometers became available there was (and still is) a lot of confusion about what "temperature" we are measuring.
(Those wretched stick-on dial things that just measure the temperature of the wall don't help this either!)


----------



## mikeh

*Re: RE: Infrared - sunlight vs. basking lamps*



lilacdragon said:


> This is very much how I see the use of a multi-T5 fixture set-up, too. I am very impressed by their possibilities.
> I have a query about basking temperatures, though.
> Are we talking about air temperatures or substrate temperatures?
> 
> I'm sure no self-respecting tortoise would be out basking in full sunlight at air temperatures of 100F, (38C) but in sunlight, at air temperatures as low as 48F (9C) I measured surface temperatures of 93F (34C) up in the Spanish Sierra Nevada, and that was the surface temperature of the backs of a group of basking wall lizards in the sunlit spot, too. There weren't any torts there (!) but a couple of days earlier at sea level we found a baby Testudo graeca at the edge of some grass clumps, and the air temperature was about 81F (27.6C), the substrate where he was standing was about 105F (40.6C) and his carapace temp was about 104F (40.2C)....
> 
> Obviously there are huge species differences in this, and I agree in principle that the main reason that people have in the past created these hot spots is because we haven't understood the need for wide basking zones. But I think also, until infrared non-contact thermometers became available there was (and still is) a lot of confusion about what "temperature" we are measuring.
> (Those wretched stick-on dial things that just measure the temperature of the wall don't help this either!)



We are talking about air temperatures. 
I am glad you shared your findings at Spanish Sierra Nevada. It would have been interesting to know what the temperature was of the plastron and the core of that tortoise. I am willing to bet that if you took the tortoise into shade and measured its carapace temperature, it would be way down from 104F within seconds. Radiant heat has different intensities as we know. Midday sun in the summer will penetrate much deeper then winter sun, even though winter or shallow angle will still heat up the very top layer to high temperatures. What time of a year, time of day did you happen to be there? While the suns radiant heat was heating top of the tortoises shell a convection cooling of ambient 81F was having an effect on its entire shell. Was there air movement or wind, which would amplify the convection effect. All these thermo effects combined play a role as a whole for tortoise thermo regulating. Very interesting stuff indeed.

To make things more interesting here is an image of our surviver test subject, happily thermo regulating (basking) for couple hours strictly by convection in a 91F fan circulated air with no overhead radiant heat source. Its worth pointing that after the fan was turned off and ambient temp was brought to 84F, his carapace temp was still at 89F 30mins after suggesting his core was at the same temperature.



And here utilizing convection, conduction and radiant heat, from warm circulated air, and heated rocks. Again, no overhead radiant heat source. 



We don't need to be stuck SOLELY on overhead radiant heat sources with arid species. A combination may be most ideal to reduce undesired indoor IRA effects.

I am glad you share similar vision on T5HO lights Frances. More testing will be done. On the last note Id like to ask, do we know what CORE temperature do arid species strive to reach during the day?


----------



## lilacdragon

mikeh said:


> We are talking about air temperatures.



I think it will become increasingly important to state this, because if an owner is using an infrared non-contact thermometer to check temperatures, they will never be reading air temperatures in areas receiving infrared radiation. I think there could be a big risk of people not providing enough heat, because they are keeping the SURFACE temperature in the basking zone at a level more appropriate for the AIR temperature....
As you in effect point out, you will only get surface and air temperatures equal, in shade.
It is not therefore necessarily a problem if the basking zone surface temperature, or carapace temperature, is 104F. But it IS a problem if it is only reaching 84F and the tortoise wants to bring its core temperature up to 89F...



> I am glad you shared your findings at Spanish Sierra Nevada. It would have been interesting to know what the temperature was of the plastron and the core of that tortoise. I am willing to bet that if you took the tortoise into shade and measured its carapace temperature, it would be way down from 104F within seconds. Radiant heat has different intensities as we know. Midday sun in the summer will penetrate much deeper then winter sun, even though winter or shallow angle will still heat up the very top layer to high temperatures. What time of a year, time of day did you happen to be there? While the suns radiant heat was heating top of the tortoises shell a convection cooling of ambient 81F was having an effect on its entire shell. Was there air movement or wind, which would amplify the convection effect. All these thermo effects combined play a role as a whole for tortoise thermo regulating. Very interesting stuff indeed.



I did not pick the little tortoise up, or move him around so the only measurements I have are for surface and carapace temperatures (Infrared n-c thermometer), air temperature (gas probe on an ordinary thermocouple thermometer) and UVI (Solarmeter 6.4). I didn't have a humidity meter with me, unfortunately.

Here are some photos:
Air and substrate temperatures






Carapace temperature:





UVI:




The little guy was in partial shade as you can see. The local time was 13:22 on May 19th. (This is about 30mins before the solar mid-day, owing to Daylight Saving Time and the location of the site). Out in the open, at human height, the UVI was 6.5.

Here are the toasty warm lizards basking in air temperature 9C:







> On the last note Id like to ask, do we know what CORE temperature do arid species strive to reach during the day?


I don't know, but I think if you have access to some journals the answer will be there. (Unfortunately I don't have any university library access so rely on friends who have, or the occasional one uploaded to Researchgate or someone's website.)
Here are abstracts for the sort of thing you are looking for. Squint and you can guess at the numbers on some of the graphs....
http://www.sciencedirect.com/science/article/pii/S0306456513000181
http://www.sciencedirect.com/science/article/pii/S030645651300017X

Best wishes,
Frances


----------



## gtc

mikeh said:


> lilacdragon said:
> 
> 
> 
> MikeH - this is a really great piece of research!
> For species that don't need high basking temperatures (I guess that includes most tortoises?) this looks really worth pursuing!!
> I'm not sure that one Reptisun 5.0 tube in a reflector at 14" distance is giving sufficient UVB. I'll need to dig out some charts and see what levels you're likely to be getting... But of course you've got the ability to swap around any of the 4 tubes into UV versions, and there are different "strengths" of UVB as well...
> 
> I too thought at first, like Nearpass, that it was covering the whole enclosure but MikeH's new photo makes it look ideal for a pen that size.
> 
> (I also got a shock when I first read about tying the tortoise down with cable ties!  ... then I read about cutting it in half, too, and I decided this must be a joke and I obviously have no sense of humour....  )
> 
> 
> 
> 
> Yes, well Frances that part of the experiment didn't exactly work out. When the tortoise seen the potato and squash being cut in half he bolted immediately. Unfortunately by the time I found him, his temperature has dropped considerably, thus going forward the data would render rather useless.
> 
> Reptisun 5.0 had no real meaning to the test. It just happen to be on hand. Like you said bulbs can be swapped out in countless configurations to achieve any desired UVB output to match height that yields desires basking temperature without baking off the humidity.
> 
> And that is whats so great about multi tube T5HO lights, versatility. (For example, If the fixture was at 12" height, it would have yielded basking temp higher still then in the test for those wanting 95F. Two Reptisun 5.0 or Arcadia D3 6% installed in the outer positions would create such a very nice large UVB area.) Higher temperatures still can be achieved with 6 and 8 tube fixtures. They don't have to 4' in length, 24" 6 or 8 tube fixture will create an area of even higher basking temperatures.
> 
> I don't think any hatchling or smaller tortoise utilizes 100F direct midday sunlight for basking. So why are we creating these 100-110F hot spots with basking bulbs. Well, because thats what we know, to compensate with tiny basking spot, and to heat up the surrounding ambient temp with the same light.
> 
> I think these multi tube T5HO lights can be used for basking and heating on any hatchling and smaller tortoises without much impact on humidity, creating milder but BIG and EVEN temp basking area.
> That being said, I do not see these lights alone being efficient to heat up a 50lbs Sulcata, but neither will a 100-200watt basking bulb, baking top of the carapace.
> 
> These multi tube T5HO lights appear to be very bright, but even at 20,000 lumes, it is still far cry from sunny day outside. Its just that indoor lighting is very dark and we are used to gloomy, dark enclosures. And For tropical spieces, no problem, plants, plants, plants, they love these lights. Create a nice plant canopy to break up the light and your tropical tortoise will bask under. Grass, clover, and weeds grow like crazy with these lights. After all these are grow lights.
Click to expand...


This might be a silly question but in what way are the 4 T5 tubes better than a 160W mvb in a closed chamber? Both create basking zones That can be considered large for small tortoise species and humidity should not be an issue with closed chambers. I am sorry if I have missed something here.

By the way great job with your setup and research.


----------



## gtc

gtc said:


> mikeh said:
> 
> 
> 
> 
> 
> lilacdragon said:
> 
> 
> 
> MikeH - this is a really great piece of research!
> For species that don't need high basking temperatures (I guess that includes most tortoises?) this looks really worth pursuing!!
> I'm not sure that one Reptisun 5.0 tube in a reflector at 14" distance is giving sufficient UVB. I'll need to dig out some charts and see what levels you're likely to be getting... But of course you've got the ability to swap around any of the 4 tubes into UV versions, and there are different "strengths" of UVB as well...
> 
> I too thought at first, like Nearpass, that it was covering the whole enclosure but MikeH's new photo makes it look ideal for a pen that size.
> 
> (I also got a shock when I first read about tying the tortoise down with cable ties!  ... then I read about cutting it in half, too, and I decided this must be a joke and I obviously have no sense of humour....  )
> 
> 
> 
> 
> Yes, well Frances that part of the experiment didn't exactly work out. When the tortoise seen the potato and squash being cut in half he bolted immediately. Unfortunately by the time I found him, his temperature has dropped considerably, thus going forward the data would render rather useless.
> 
> Reptisun 5.0 had no real meaning to the test. It just happen to be on hand. Like you said bulbs can be swapped out in countless configurations to achieve any desired UVB output to match height that yields desires basking temperature without baking off the humidity.
> 
> And that is whats so great about multi tube T5HO lights, versatility. (For example, If the fixture was at 12" height, it would have yielded basking temp higher still then in the test for those wanting 95F. Two Reptisun 5.0 or Arcadia D3 6% installed in the outer positions would create such a very nice large UVB area.) Higher temperatures still can be achieved with 6 and 8 tube fixtures. They don't have to 4' in length, 24" 6 or 8 tube fixture will create an area of even higher basking temperatures.
> 
> I don't think any hatchling or smaller tortoise utilizes 100F direct midday sunlight for basking. So why are we creating these 100-110F hot spots with basking bulbs. Well, because thats what we know, to compensate with tiny basking spot, and to heat up the surrounding ambient temp with the same light.
> 
> I think these multi tube T5HO lights can be used for basking and heating on any hatchling and smaller tortoises without much impact on humidity, creating milder but BIG and EVEN temp basking area.
> That being said, I do not see these lights alone being efficient to heat up a 50lbs Sulcata, but neither will a 100-200watt basking bulb, baking top of the carapace.
> 
> These multi tube T5HO lights appear to be very bright, but even at 20,000 lumes, it is still far cry from sunny day outside. Its just that indoor lighting is very dark and we are used to gloomy, dark enclosures. And For tropical spieces, no problem, plants, plants, plants, they love these lights. Create a nice plant canopy to break up the light and your tropical tortoise will bask under. Grass, clover, and weeds grow like crazy with these lights. After all these are grow lights.
> 
> Click to expand...
> 
> 
> This might be a silly question but in what way are the 4 T5 tubes better than a 160W mvb in a closed chamber? Both create basking zones That can be considered large for small tortoise species and humidity should not be an issue with closed chambers. I am sorry if I have missed something here.
> 
> By the way great job with your setup and research.
Click to expand...



I re-read the posts and I think I understand now. The advantage is a even and wider basking area with a small effect on humidity. Mimics the sun more closely. Very cool. What basking temps would you recommend with this setup? How many UVB 5.0 tubes, 2 of 4 maybe?


----------



## mikeh

gtc, yes, you got idea.....
Ideally you want to create same basking temperature as with regular basking lights. I would go with 95F for arid species. Because the heat output of T5HO is not as intense the height to create this basking temp will depend on weather you have closed chamber and size or open table and room temperature. It could be anything from 10"-18", that will also determine strength and number of UVB tubes. 
If you provide some details I can give you better idea on tubes.


----------



## gtc

mikeh said:


> gtc, yes, you got idea.....
> Ideally you want to create same basking temperature as with regular basking lights. I would go with 95F for arid species. Because the heat output of T5HO is not as intense the height to create this basking temp will depend on weather you have closed chamber and size or open table and room temperature. It could be anything from 10"-18", that will also determine strength and number of UVB tubes.
> If you provide some details I can give you better idea on tubes.



Thank you, 

The attached photo is not current, I have covered about 90-95% of the top now in order to keep humidity at basking zone between 25-30% and 60-70% in rest of enclosure. I use a 160W powersun mvb now. 

Due to the climate my greek lives about 9 months indoors and always sleeps indoors.

I am considering changing to your setup after reading all these interesting posts, especially when in about 2 years I plan to make a very large indoor enclosure and I wish to have large basking zones.

My biggest concern is if uvb tubes (compared to mvb) can provide enough uvb for adequate vit D synthesis in torts that dont get a lot outside time. Also since the future indoor enclosure will be open and about 3 yards by 6 yards I wonder if the tubes will be able to produce a hot enough basking temp?


----------



## mikeh

*Re: RE: Infrared - sunlight vs. basking lamps*



gtc said:


> mikeh said:
> 
> 
> 
> gtc, yes, you got idea.....
> Ideally you want to create same basking temperature as with regular basking lights. I would go with 95F for arid species. Because the heat output of T5HO is not as intense the height to create this basking temp will depend on weather you have closed chamber and size or open table and room temperature. It could be anything from 10"-18", that will also determine strength and number of UVB tubes.
> If you provide some details I can give you better idea on tubes.
> 
> 
> 
> 
> Thank you,
> 
> The attached photo is not current, I have covered about 90-95% of the top now in order to keep humidity at basking zone between 25-30% and 60-70% in rest of enclosure. I use a 160W powersun mvb now.
> 
> Due to the climate my greek lives about 9 months indoors and always sleeps indoors.
> 
> I am considering changing to your setup after reading all these interesting posts, especially when in about 2 years I plan to make a very large indoor enclosure and I wish to have large basking zones.
> 
> My biggest concern is if uvb tubes (compared to mvb) can provide enough uvb for adequate vit D synthesis in torts that dont get a lot outside time. Also since the future indoor enclosure will be open and about 3 yards by 6 yards I wonder if the tubes will be able to produce a hot enough basking temp?
Click to expand...


On your biggest concern of UVB: T5HO UVB tubes are superior to MVBs. They mimic suns spectrum better then MVBs and last much longer. MVBs (Mega Ray may be the exception) are known to fail within as little as one month, rendering them useless for UVB. T5HO Arcadia D3+ are good for up to one year. In short T5HO tubes are better choice for UVB. 

For your current set up 24" T5HO quad fixture seems ideal. Fixture placed in the middle with most of the enclosure covered as you have now. This would increase your basking area humidity to 45%-55% with rest remaining at your current levels. 
Here is link to a hydrofarm fixture. 

http://www.megagrowers.com/t5-designer-2ft-4-tube-fixture-w-bulbs/?gclid=CMaXx66c77sCFYtQOgodGDIAjQ

It comes with grow lights. This will allow you to determine at what height you will set the fixture to obtain desired basking temp. The ideal height will then determine what strength UVB tube(s) are appropriate.

Heights 10"-12" will yield lover UVB tubes such as Zoomed 5% or Arcadia D3+ 6%. 
Height of 15-18" will yeild higher UVB tubes, Zoomed 10% or Arcadia D3+12%.
Either set up with two uvb tubes placed in the outer positions of the fixture seem ideal, with grow lights on the inside positions. 

For your future 3yards by 6yards enclosure you would need 4' 6-8tube fixture or maybe even creating two basking areas with two large fixtures. 

___________________________________

If your tortoise spends hours on end under the MVB you have, it is having a drying effect on its carapace not only by lowering humidity to very low levels under the bulb but also by IRA spectrum the heat bulbs produce. It is suggested this may be one of the factors contributing to pyramiding, that's what this thread is about. 

Since T5HO lights don't dry out the humidity it would seem they don't produce as high of IRA spectrum thus not having this negative effect on the shell, although testing is needed. Hopefully one of our members will test them with rest of the heat lights in next couple of months to give us better answers.


----------



## gtc

mikeh said:


> gtc said:
> 
> 
> 
> 
> 
> mikeh said:
> 
> 
> 
> gtc, yes, you got idea.....
> Ideally you want to create same basking temperature as with regular basking lights. I would go with 95F for arid species. Because the heat output of T5HO is not as intense the height to create this basking temp will depend on weather you have closed chamber and size or open table and room temperature. It could be anything from 10"-18", that will also determine strength and number of UVB tubes.
> If you provide some details I can give you better idea on tubes.
> 
> 
> 
> 
> Thank you,
> 
> The attached photo is not current, I have covered about 90-95% of the top now in order to keep humidity at basking zone between 25-30% and 60-70% in rest of enclosure. I use a 160W powersun mvb now.
> 
> Due to the climate my greek lives about 9 months indoors and always sleeps indoors.
> 
> I am considering changing to your setup after reading all these interesting posts, especially when in about 2 years I plan to make a very large indoor enclosure and I wish to have large basking zones.
> 
> My biggest concern is if uvb tubes (compared to mvb) can provide enough uvb for adequate vit D synthesis in torts that dont get a lot outside time. Also since the future indoor enclosure will be open and about 3 yards by 6 yards I wonder if the tubes will be able to produce a hot enough basking temp?
> 
> Click to expand...
> 
> 
> On your biggest concern of UVB: T5HO UVB tubes are superior to MVBs. They mimic suns spectrum better then MVBs and last much longer. MVBs (Mega Ray may be the exception) are known to fail within as little as one month, rendering them useless for UVB. T5HO Arcadia D3+ are good for up to one year. In short T5HO tubes are better choice for UVB.
> 
> For your current set up 24" T5HO quad fixture seems ideal. Fixture placed in the middle with most of the enclosure covered as you have now. This would increase your basking area humidity to 45%-55% with rest remaining at your current levels.
> Here is link to a hydrofarm fixture.
> 
> http://www.megagrowers.com/t5-designer-2ft-4-tube-fixture-w-bulbs/?gclid=CMaXx66c77sCFYtQOgodGDIAjQ
> 
> It comes with grow lights. This will allow you to determine at what height you will set the fixture to obtain desired basking temp. The ideal height will then determine what strength UVB tube(s) are appropriate.
> 
> Heights 10"-12" will yield lover UVB tubes such as Zoomed 5% or Arcadia D3+ 6%.
> Height of 15-18" will yeild higher UVB tubes, Zoomed 10% or Arcadia D3+12%.
> Either set up with two uvb tubes placed in the outer positions of the fixture seem ideal, with grow lights on the inside positions.
> 
> For your future 3yards by 6yards enclosure you would need 4' 6-8tube fixture or maybe even creating two basking areas with two large fixtures.
> 
> ___________________________________
> 
> If your tortoise spends hours on end under the MVB you have, it is having a drying effect on its carapace not only by lowering humidity to very low levels under the bulb but also by IRA spectrum the heat bulbs produce. It is suggested this may be one of the factors contributing to pyramiding, that's what this thread is about.
> 
> Since T5HO lights don't dry out the humidity it would seem they don't produce as high of IRA spectrum thus not having this negative effect on the shell, although testing is needed. Hopefully one of our members will test them with rest of the heat lights in next couple of months to give us better answers.
Click to expand...


First of all, thank you for the great info. I found a place in my country that sells the exact same fixture you recommended (it costs 300 dollars here though).

Its funny, I went for a mvb + ceramic base with dome + zoomed light stand (which I paid over 600 dollars for here, everything is so cheap in the USA  ) since I read that mvb's produced a better spectrum that T5 tubes. My last powersun lasted for the full 9 months I used it, and I just bought a new one a month ago. Do you think that pyramiding is possible even if I go from 90% cover to 100% cover and increase the humidity to maybe 35-40% under the bulb? If so I will go ahead that buy the new setup right away. Otherwise I am considering waiting 9 more months and when the time comes to replace my mvb to switch to your setup. The most important thing the the well being of my tortoise.


----------



## mikeh

*Re: RE: Infrared - sunlight vs. basking lamps*



gtc said:


> mikeh said:
> 
> 
> 
> 
> 
> gtc said:
> 
> 
> 
> 
> 
> mikeh said:
> 
> 
> 
> gtc, yes, you got idea.....
> Ideally you want to create same basking temperature as with regular basking lights. I would go with 95F for arid species. Because the heat output of T5HO is not as intense the height to create this basking temp will depend on weather you have closed chamber and size or open table and room temperature. It could be anything from 10"-18", that will also determine strength and number of UVB tubes.
> If you provide some details I can give you better idea on tubes.
> 
> 
> 
> 
> Thank you,
> 
> The attached photo is not current, I have covered about 90-95% of the top now in order to keep humidity at basking zone between 25-30% and 60-70% in rest of enclosure. I use a 160W powersun mvb now.
> 
> Due to the climate my greek lives about 9 months indoors and always sleeps indoors.
> 
> I am considering changing to your setup after reading all these interesting posts, especially when in about 2 years I plan to make a very large indoor enclosure and I wish to have large basking zones.
> 
> My biggest concern is if uvb tubes (compared to mvb) can provide enough uvb for adequate vit D synthesis in torts that dont get a lot outside time. Also since the future indoor enclosure will be open and about 3 yards by 6 yards I wonder if the tubes will be able to produce a hot enough basking temp?
> 
> Click to expand...
> 
> 
> On your biggest concern of UVB: T5HO UVB tubes are superior to MVBs. They mimic suns spectrum better then MVBs and last much longer. MVBs (Mega Ray may be the exception) are known to fail within as little as one month, rendering them useless for UVB. T5HO Arcadia D3+ are good for up to one year. In short T5HO tubes are better choice for UVB.
> 
> For your current set up 24" T5HO quad fixture seems ideal. Fixture placed in the middle with most of the enclosure covered as you have now. This would increase your basking area humidity to 45%-55% with rest remaining at your current levels.
> Here is link to a hydrofarm fixture.
> 
> http://www.megagrowers.com/t5-designer-2ft-4-tube-fixture-w-bulbs/?gclid=CMaXx66c77sCFYtQOgodGDIAjQ
> 
> It comes with grow lights. This will allow you to determine at what height you will set the fixture to obtain desired basking temp. The ideal height will then determine what strength UVB tube(s) are appropriate.
> 
> Heights 10"-12" will yield lover UVB tubes such as Zoomed 5% or Arcadia D3+ 6%.
> Height of 15-18" will yeild higher UVB tubes, Zoomed 10% or Arcadia D3+12%.
> Either set up with two uvb tubes placed in the outer positions of the fixture seem ideal, with grow lights on the inside positions.
> 
> For your future 3yards by 6yards enclosure you would need 4' 6-8tube fixture or maybe even creating two basking areas with two large fixtures.
> 
> ___________________________________
> 
> If your tortoise spends hours on end under the MVB you have, it is having a drying effect on its carapace not only by lowering humidity to very low levels under the bulb but also by IRA spectrum the heat bulbs produce. It is suggested this may be one of the factors contributing to pyramiding, that's what this thread is about.
> 
> Since T5HO lights don't dry out the humidity it would seem they don't produce as high of IRA spectrum thus not having this negative effect on the shell, although testing is needed. Hopefully one of our members will test them with rest of the heat lights in next couple of months to give us better answers.
> 
> Click to expand...
> 
> 
> First of all, thank you for the great info. I found a place in my country that sells the exact same fixture you recommended (it costs 300 dollars here though).
> 
> Its funny, I went for a mvb + ceramic base with dome + zoomed light stand (which I paid over 600 dollars for here, everything is so cheap in the USA  ) since I read that mvb's produced a better spectrum that T5 tubes. My last powersun lasted for the full 9 months I used it, and I just bought a new one a month ago. Do you think that pyramiding is possible even if I go from 90% cover to 100% cover and increase the humidity to maybe 35-40% under the bulb? If so I will go ahead that buy the new setup right away. Otherwise I am considering waiting 9 more months and when the time comes to replace my mvb to switch to your setup. The most important thing the the well being of my tortoise.
Click to expand...


Just because MVB lights up doesn't mean it is producing UVB. Unless you measured it with UVB meter there is no way of knowing. I seriously doubt power sun would produce UVB at 9 or even 6 months. 

I am not sure where you read MVB produces better UVB spectrum then T5HO, but that sounds like marketing nonsense. Independent tests tell a very different picture. 



Since things are so expensive in Norway and you have a new MVB, chances are you are OK for next two or so months. I would attempt to increase the humidity under the light without effecting humidity in rest of the enclosure, which seems ideal as you have it. This may involve misting the substrate just under the light couple times a day. Misting the tortoise may also help. But its not just the very low humidity under the bulb, its also the IRA the bulb produces. 

You have had the tortoise now for many months, if its growing smooth, shell is hard , along with balanced nutrition chances are things are going well for him/her in your set up. 

When the time comes in next couple months to replace the MVB, you can then decide to switch to T5HO. One other factor is day time room temperature the tortoise table is in. Since T5HO lights are not as intense, they may not create sufficient heat in room of ambient temp. below 70F.


----------



## gtc

mikeh said:


> gtc said:
> 
> 
> 
> 
> 
> mikeh said:
> 
> 
> 
> 
> 
> gtc said:
> 
> 
> 
> 
> 
> mikeh said:
> 
> 
> 
> gtc, yes, you got idea.....
> Ideally you want to create same basking temperature as with regular basking lights. I would go with 95F for arid species. Because the heat output of T5HO is not as intense the height to create this basking temp will depend on weather you have closed chamber and size or open table and room temperature. It could be anything from 10"-18", that will also determine strength and number of UVB tubes.
> If you provide some details I can give you better idea on tubes.
> 
> 
> 
> 
> Thank you,
> 
> The attached photo is not current, I have covered about 90-95% of the top now in order to keep humidity at basking zone between 25-30% and 60-70% in rest of enclosure. I use a 160W powersun mvb now.
> 
> Due to the climate my greek lives about 9 months indoors and always sleeps indoors.
> 
> I am considering changing to your setup after reading all these interesting posts, especially when in about 2 years I plan to make a very large indoor enclosure and I wish to have large basking zones.
> 
> My biggest concern is if uvb tubes (compared to mvb) can provide enough uvb for adequate vit D synthesis in torts that dont get a lot outside time. Also since the future indoor enclosure will be open and about 3 yards by 6 yards I wonder if the tubes will be able to produce a hot enough basking temp?
> 
> Click to expand...
> 
> 
> On your biggest concern of UVB: T5HO UVB tubes are superior to MVBs. They mimic suns spectrum better then MVBs and last much longer. MVBs (Mega Ray may be the exception) are known to fail within as little as one month, rendering them useless for UVB. T5HO Arcadia D3+ are good for up to one year. In short T5HO tubes are better choice for UVB.
> 
> For your current set up 24" T5HO quad fixture seems ideal. Fixture placed in the middle with most of the enclosure covered as you have now. This would increase your basking area humidity to 45%-55% with rest remaining at your current levels.
> Here is link to a hydrofarm fixture.
> 
> http://www.megagrowers.com/t5-designer-2ft-4-tube-fixture-w-bulbs/?gclid=CMaXx66c77sCFYtQOgodGDIAjQ
> 
> It comes with grow lights. This will allow you to determine at what height you will set the fixture to obtain desired basking temp. The ideal height will then determine what strength UVB tube(s) are appropriate.
> 
> Heights 10"-12" will yield lover UVB tubes such as Zoomed 5% or Arcadia D3+ 6%.
> Height of 15-18" will yeild higher UVB tubes, Zoomed 10% or Arcadia D3+12%.
> Either set up with two uvb tubes placed in the outer positions of the fixture seem ideal, with grow lights on the inside positions.
> 
> For your future 3yards by 6yards enclosure you would need 4' 6-8tube fixture or maybe even creating two basking areas with two large fixtures.
> 
> ___________________________________
> 
> If your tortoise spends hours on end under the MVB you have, it is having a drying effect on its carapace not only by lowering humidity to very low levels under the bulb but also by IRA spectrum the heat bulbs produce. It is suggested this may be one of the factors contributing to pyramiding, that's what this thread is about.
> 
> Since T5HO lights don't dry out the humidity it would seem they don't produce as high of IRA spectrum thus not having this negative effect on the shell, although testing is needed. Hopefully one of our members will test them with rest of the heat lights in next couple of months to give us better answers.
> 
> Click to expand...
> 
> 
> First of all, thank you for the great info. I found a place in my country that sells the exact same fixture you recommended (it costs 300 dollars here though).
> 
> Its funny, I went for a mvb + ceramic base with dome + zoomed light stand (which I paid over 600 dollars for here, everything is so cheap in the USA  ) since I read that mvb's produced a better spectrum that T5 tubes. My last powersun lasted for the full 9 months I used it, and I just bought a new one a month ago. Do you think that pyramiding is possible even if I go from 90% cover to 100% cover and increase the humidity to maybe 35-40% under the bulb? If so I will go ahead that buy the new setup right away. Otherwise I am considering waiting 9 more months and when the time comes to replace my mvb to switch to your setup. The most important thing the the well being of my tortoise.
> 
> Click to expand...
> 
> 
> Just because MVB lights up doesn't mean it is producing UVB. Unless you measured it with UVB meter there is no way of knowing. I seriously doubt power sun would produce UVB at 9 or even 6 months.
> 
> I am not sure where you read MVB produces better UVB spectrum then T5HO, but that sounds like marketing nonsense. Independent tests tell a very different picture.
> 
> 
> 
> Since things are so expensive in Norway and you have a new MVB, chances are you are OK for next two or so months. I would attempt to increase the humidity under the light without effecting humidity in rest of the enclosure, which seems ideal as you have it. This may involve misting the substrate just under the light couple times a day. Misting the tortoise may also help. But its not just the very low humidity under the bulb, its also the IRA the bulb produces.
> 
> You have had the tortoise now for many months, if its growing smooth, shell is hard , along with balanced nutrition chances are things are going well for him/her in your set up.
> 
> When the time comes in next couple months to replace the MVB, you can then decide to switch to T5HO. One other factor is day time room temperature the tortoise table is in. Since T5HO lights are not as intense, they may not create sufficient heat in room of ambient temp. below 70F.
Click to expand...


Sounds like a good plan. I'll post pics of my new setup and the temps\humidity I get once I get it up and running


----------



## gtc

Hi Mike,

I have been seriously looking into trying the new setup you tested. I am planing to get the 6% tubes because I think I will need to get the tubes quite low in order to get a basking temp of 95 F.

Before I start buying the fixture and tubes I have 2 questions:

1. I have read in a forum that someone with a solarmeter tested the arcadia T5 tubes and found that they produced too much UVB and had to put a mesh screen between the tube and the tort to lower the output. I am wondering if you have a solarmeter and if you have tested the output of the tube with the fixture you recommended with 1 arcadia 6% bulb vs 2 6% bulbs. I wonder if 2 might give too much uvb?

2. Have you started using this setup for any of your tortoises or are you still using the tubes with heaters + fan?


----------



## mikeh

*Re: RE: Infrared - sunlight vs. basking lamps*



gtc said:


> Hi Mike,
> 
> I have been seriously looking into trying the new setup you tested. I am planing to get the 6% tubes because I think I will need to get the tubes quite low in order to get a basking temp of 95 F.
> 
> Before I start buying the fixture and tubes I have 2 questions:
> 
> 1. I have read in a forum that someone with a solarmeter tested the arcadia T5 tubes and found that they produced too much UVB and had to put a mesh screen between the tube and the tort to lower the output. I am wondering if you have a solarmeter and if you have tested the output of the tube with the fixture you recommended with 1 arcadia 6% bulb vs 2 6% bulbs. I wonder if 2 might give too much uvb?
> 
> 2. Have you started using this setup for any of your tortoises or are you still using the tubes with heaters + fan?



I have not tested the bulbs with UVB meter, I don't currently have one. Arcadia website has charts of UVB output levels for different UVB tubes at different heights under each product to guide you. 

I only have 12% tubes, even though I haven't measured , fresh out of the box the tubes do indeed have very high UVB/UVA output. At the initial power up, handling the powered fixture with my hands I could slightly smell my skin having the same scent as when melanin in the skin oxidizes under intense UVA/UVB in tanning beds.
As a precautionary measure I always let the Arcadia tubes burn in for 100 hours prior to use. The "access" output is lost during this burn in period, after which the output stabilizes at somewhat lower levels. 

You can surely start with one 6% UVB tube. Adding additional tubes if needed later will increase UVB. (Frances pointed out earlier that in London Zoo the UVB set up for adult Aldabra tortoises consisting of multiple 4 foot, 6tube fixtures (equipped with all Arcadia 3D+ 12% tubes) is positioned 7 feet up of the ground for ideal UVB levels. This gives a rough picture of how clustering the UVB tubes increases levels.
You can also observe how your tortoise utilizes the fixture. If he spends significant amount of day under then one tube could be just fine, if less time perhaps two tubes to slightly increase area and uvb output to compensate. What's ideal?...I simply do not know, I don't think anyone has come up with a set protocol. I would read up as much as I can on your torts species and their natural habitat, to get some picture of how much UVB, what levels and hours of day on average is received in nature at your torts age, then try to replicate it based on torts behavior inside. But generally speaking arid tortoises housed indoors are UVB deprived receiving much less UVB then outdoor tortoises. 

My current set up for 8month leopard consists of 4'x2'x20" fully closed chamber (glass on 3sides), 48"T5HO 2tube fixture. One Arcadia 12% UVB and one none UVB tube. The height changes with terrain under the fixture from 14-17". There is a 80watt supplemental heat cable that also serves as night heat, fan is primarily used to create HOT days. The heat cable is on thermostat to pick up any slack. As the room temperature is always at 62-64F these days, the cable does cycle on good amount. (I used the 2bulb 4' fixture fixture because it was on hand, if I was doing the set up from scratch I would have chosen 4bulb 2'fixture.)
The tort spends 6-8 hours a day in the vicinity of the fixture. I am going to purely speculate here, but my guess is with this set up ( how much time he spends under UVB/UVA) he is receiving amounts of ideal to higher levels. Any new bright white growth gets darker tan within few days, lots of his older growth is still changing from tan to black and good amount of his new growth is coming in black as well. I believe this darkening could be related to UVB/UVA exposure in leopards. His skin color especially on the top of his head has gotten darker, his front feet as well. His shell is very solid, with a slight give only at the new growth on the plastron. No vit D3 is supplemented. He has been strictly indoors since end of august. He is active all day with ravenous appetite on cool days and more relaxed on HOT days spending hours on end basking and not fixated on food as much. 

Hope all these details help to some extent. You will have to play with the set up to get it where you want it, for me that's fun part of it. It will also reveal lots about behaviors, preferences and habits of your tort.


----------



## gtc

Update and preliminary test results:

My 4 x T5 tube fixture arrived! It only contains the growing tubes that came with it so far....been on for *1 hour at 10 inches above substrate level* and the temps (analog and digital thermometer) both show* 92 F*. Ambient room temp was* 73 F*. Humidity dropped from 35 % to 26% right under the lamp and its keeping at 75 F and 52 % in the rest of the enclosure.

Its late so my greek didn't bother waking and coming out of his hide during testing.

So......not totally sure how I feel about these test results yet. 

(possibly) negative aspects:10 inches is kind of close and 92 F kind of low.....

2 BIG questions:

1. is 92 F a warm enough basking area for a greek tortoise?

2. I would really like to use 2 arcadia T5 6% tubes in the fixture, but is 10 inches from substrate (even closer then from top of shell) too close??


From arcadia web site:

Arcadia T5 â€“ 16mm D3 6% lamp and reflector

10cms (4 inches) 289uw/cm2
20cms. (7.8 inches)	145uw/cm2
30cms. (12 inches)	83uw/cm2
40cms. (15.7 inches)	56uw/cm2


----------



## mikeh

*Re: RE: Infrared - sunlight vs. basking lamps*



gtc said:


> Update and preliminary test results:
> 
> My 4 x T5 tube fixture arrived! It only contains the growing tubes that came with it so far....been on for *1 hour at 10 inches above substrate level* and the temps (analog and digital thermometer) both show* 92 F*. Ambient room temp was* 73 F*. Humidity dropped from 35 % to 26% right under the lamp and its keeping at 75 F and 52 % in the rest of the enclosure.
> 
> Its late so my greek didn't bother waking and coming out of his hide during testing.
> 
> So......not totally sure how I feel about these test results yet.
> 
> (possibly) negative aspects:10 inches is kind of close and 92 F kind of low.....
> 
> 2 BIG questions:
> 
> 1. is 92 F a warm enough basking area for a greek tortoise?
> 
> 2. I would really like to use 2 arcadia T5 6% tubes in the fixture, but is 10 inches from substrate (even closer then from top of shell) too close??
> 
> 
> From arcadia web site:
> 
> Arcadia T5 â€“ 16mm D3 6% lamp and reflector
> 
> 10cms (4 inches) 289uw/cm2
> 20cms. (7.8 inches)	145uw/cm2
> 30cms. (12 inches)	83uw/cm2
> 40cms. (15.7 inches)	56uw/cm2



To further raise the temperature by couple degrees place very dark colored flat piece of slate rock under the light, size of about 1x1 foot. The rock will absorb the heat and then radiate it out. (Dark tile may work as well). Tortoises are very sensitive to heat and will easily find the warmest spot on top of the rock if it desires. You can also place couple plants just outside of the edge of the fixture helping in keeping the localized heat in the area. Further you can close the gap opening around the sides of the fixture. With these combinations you should be able to bring the temp. up to at least 95. If you wish to raise the humidity slightly under the lamp, mist the substrate with water just directly under the lamp every other day or as needed. 

The distance of 10" with Arcadia D3+ 6% actually looks ideal. Below is a post from Frances from another thread. She is an expert on UVB. It explains the conversion of the artificial UVB to match outdoor UV index. In your case at 10" it translates to UV index 3-4 which is equivalent to earlier morning sun in the tropics. According to Arcadia chart at 10" it produces +/-120 microwats. 120:31.4 as per Frances formula gives UV index equivalent to 3.81 outdoors. Not too high at all. 

Frances post on UV conversions:

This is going to be a long post. But I honestly don't know any really simple way of explaining this, so I'm going to work through it as carefully as I can, although I know it's a  sort of thing to do to anyone so late at night... ï¿¼



Yes. ï¿¼ You will get a very good idea of how the UVB changes with time of day and with the seasons - and find the best places for your tortoises to sun-bask.




This is where the problem is, I'm afraid.

The Solarmeter 6.2 is designed to read the whole UVB spectrum. This includes shorter wavelengths, which are very effective at creating vitamin D, and longer wavelengths which have a less powerful effect. Sunlight has a lot of these longer wavelengths, which contribute a great deal to the reading on a Solarmeter 6.2.

But Reptile lamps almost all have a different spectrum from sunlight.
Some have a spectrum that is fairly similar - like most metal halide lamps and fluorescent tubes. Usually these have UVB spectra rather similar to strong tropical midday sunlight - powerful, but fine if positioned at the right distance.
Others, like many of the mercury vapour tubes and a few fluorescent tubes, have a much greater proportion of their UVB in the shorter, more reactive wavelengths. A small amount of this can have as powerful an effect on the skin as a large amount of longer-wavelength UVB.

But the Solarmeter 6.2 can't distinguish between "shorter wavelength" and "longer wavelength" UVB. It just gives you a Total UVB reading.
So... for some tubes and quite a few mercury vapour lamps, you don't want to match "full sunlight" values, with a Solarmeter 6.2 reading, because although (for example) 300 ÂµW/cmÂ² of sunlight is typical of sunlight at about 9.30 - 10.00am in the tropics, and safe enough.... 300 ÂµW/cmÂ² of UVB from some lamps would contain far too much shorter-wavelength UVB, and could even be hazardous for delicate eyes and skin.

The Solarmeter 6.5 is designed to respond more strongly to the shorter wavelength UVB (by a filter selectively reducing the longer wavelength UVB that reaches the sensor) its readings from lamps and from the sun are much better correlated.
So it is possible to "match" lamp and sunlight readings and be fairly certain that with a good quality lamp, the UV Index you are reading at the tortoise's basking level isn't far off the same "strength" as sunlight giving you the same reading.

Lots of people have asked me if there's a simple formula for converting a UVB reading (ÂµW/cmÂ²) from a 6.2 meter into a UV Index reading.
I wish there was! But because each brand of lamp has a slightly different spectrum, and "new improved" products will doubtless have new spectra too, it's an everlasting game. The only way to do it is to take sets of readings from a lamp, at the same distance, from both meters and plot a graph, from which you can get what's known as a regression formula... (a conversion formula).
Here are some samples, i.e., conversion formulas I've worked out for some lamps I've tested in the last three or four years, using my pair of Solarmeters. You're welcome to use these formulae but please bear in mind that there's no way I can be certain that your lamps are exactly the same as mine; and I only did the calculation on a tiny sample of lamps. So it's not really more than an estimate... (If anyone has 2 meters and some lamps, and wants to set to work plotting some more... please do! ï¿¼ )

So: To get the approximate UV Index from a Solarmeter 6.2 reading, divide the Solarmeter 6.2 reading by the following numbers:

For a ZooMed Reptisun 5.0 or an Arcadia D3 6%UVB tube: 31.4 (average calculated from 4 lamps) 
For a ZooMed Reptisun 10.0 or an Arcadia D3+ 12%UVB tube: 32.7 (average calculated from 14 lamps)
For a 100watt ZooMed Powersun : 12.2 (average calculated from 5 lamps)
For a 125watt ExoTerra Solar Glo: 19.4 (average calculated from 3 lamps)
For a 160watt ExoTerra Solar Glo: 16.7 (average calculated from 2 lamps)
For an ExoTerra SunRay Metal Halide lamp: 36.6 (average calculated from 2 lamps, one 50W and one 70W)

To find out what the approximate Solarmeter 6.2 reading would be, at a specific UV Index, multiply the numbers by the UV Index you need.
e.g. if you want a UV Index of 2 under a ZooMed Reptisun 5.0 tube, multiply 31.4 by 2.
So UVI 2 would read about 63 ÂµW/cmÂ² under a ZooMed Reptisun 5.0 tube.... 
.....ok?

For the sun, it's really complicated because it changes depending on the height of the sun in the sky. My formula requires a calculator!
But here are some calculations I made based on a large number of paired solar readings plotted on a graph...
UVI 1 = 57ÂµW/cmÂ² 
UVI 2 = 108ÂµW/cmÂ² 
UVI 3 = 155ÂµW/cmÂ² 
UVI 7 = 301ÂµW/cmÂ² 
UVI 12 = 437ÂµW/cmÂ² 
UVI 15 = 521ÂµW/cmÂ² 

For example.... suppose I wanted to create a basking zone with a maximum UVI of 3. This is like early morning sunshine about 8.30am in the tropics.
If I was measuring sunlight the Solarmeter 6.2 might read about 150 ÂµW/cmÂ².
To match that, I would need approximately:
98 ÂµW/cmÂ² with a ZooMed Reptisun 10.0 (3 x 32.7)
37 ÂµW/cmÂ² with a 100watt ZooMed Powersun (3 x 12.2)

Does this make sense to anyone or have you all lost the will to live ï¿¼




Yes, this is what the Solarmeter 6.2 excels in. Take measurements always at the same distance from the lamp, about once a month and you will be able to see how the UVB gradually declines with age.
In the first month, most lamps lose quite a lot, but after that the output from a good quality lamp of most types remains quite good for about a full year, only declining quite slowly... It's usual to replace a lamp when it's lost 50% of the UVB it had at first. With some types, e.g., ones that don't put out a lot of heat, you can keep the basking zone UVB the same over the year by lowering the lamp a little, as necessary, as its output falls.
By taking monthly readings you may discover that some good quality bulbs will keep going for well over a year, without needing changing.
Or when they are getting a bit low for a sun-basking species, you can use them over a shade-dweller - people can sometimes get 2 or even 3 years of life out of a good lamp in this way.

Best wishes,
Frances


----------



## gtc

mikeh said:


> gtc said:
> 
> 
> 
> Update and preliminary test results:
> 
> My 4 x T5 tube fixture arrived! It only contains the growing tubes that came with it so far....been on for *1 hour at 10 inches above substrate level* and the temps (analog and digital thermometer) both show* 92 F*. Ambient room temp was* 73 F*. Humidity dropped from 35 % to 26% right under the lamp and its keeping at 75 F and 52 % in the rest of the enclosure.
> 
> Its late so my greek didn't bother waking and coming out of his hide during testing.
> 
> So......not totally sure how I feel about these test results yet.
> 
> (possibly) negative aspects:10 inches is kind of close and 92 F kind of low.....
> 
> 2 BIG questions:
> 
> 1. is 92 F a warm enough basking area for a greek tortoise?
> 
> 2. I would really like to use 2 arcadia T5 6% tubes in the fixture, but is 10 inches from substrate (even closer then from top of shell) too close??
> 
> 
> From arcadia web site:
> 
> Arcadia T5 â€“ 16mm D3 6% lamp and reflector
> 
> 10cms (4 inches) 289uw/cm2
> 20cms. (7.8 inches)	145uw/cm2
> 30cms. (12 inches)	83uw/cm2
> 40cms. (15.7 inches)	56uw/cm2
> 
> 
> 
> 
> To further raise the temperature by couple degrees place very dark colored flat piece of slate rock under the light, size of about 1x1 foot. The rock will absorb the heat and then radiate it out. (Dark tile may work as well). Tortoises are very sensitive to heat and will easily find the warmest spot on top of the rock if it desires. You can also place couple plants just outside of the edge of the fixture helping in keeping the localized heat in the area. Further you can close the gap opening around the sides of the fixture. With these combinations you should be able to bring the temp. up to at least 95. If you wish to raise the humidity slightly under the lamp, mist the substrate with water just directly under the lamp every other day or as needed.
> 
> The distance of 10" with Arcadia D3+ 6% actually looks ideal. Below is a post from Frances from another thread. She is an expert on UVB. It explains the conversion of the artificial UVB to match outdoor UV index. In your case at 10" it translates to UV index 3-4 which is equivalent to earlier morning sun in the tropics. According to Arcadia chart at 10" it produces +/-120 microwats. 120:31.4 as per Frances formula gives UV index equivalent to 3.81 outdoors. Not too high at all.
> 
> Frances post on UV conversions:
> 
> This is going to be a long post. But I honestly don't know any really simple way of explaining this, so I'm going to work through it as carefully as I can, although I know it's a  sort of thing to do to anyone so late at night... ï¿¼
> 
> 
> 
> Yes. ï¿¼ You will get a very good idea of how the UVB changes with time of day and with the seasons - and find the best places for your tortoises to sun-bask.
> 
> 
> 
> 
> This is where the problem is, I'm afraid.
> 
> The Solarmeter 6.2 is designed to read the whole UVB spectrum. This includes shorter wavelengths, which are very effective at creating vitamin D, and longer wavelengths which have a less powerful effect. Sunlight has a lot of these longer wavelengths, which contribute a great deal to the reading on a Solarmeter 6.2.
> 
> But Reptile lamps almost all have a different spectrum from sunlight.
> Some have a spectrum that is fairly similar - like most metal halide lamps and fluorescent tubes. Usually these have UVB spectra rather similar to strong tropical midday sunlight - powerful, but fine if positioned at the right distance.
> Others, like many of the mercury vapour tubes and a few fluorescent tubes, have a much greater proportion of their UVB in the shorter, more reactive wavelengths. A small amount of this can have as powerful an effect on the skin as a large amount of longer-wavelength UVB.
> 
> But the Solarmeter 6.2 can't distinguish between "shorter wavelength" and "longer wavelength" UVB. It just gives you a Total UVB reading.
> So... for some tubes and quite a few mercury vapour lamps, you don't want to match "full sunlight" values, with a Solarmeter 6.2 reading, because although (for example) 300 ÂµW/cmÂ² of sunlight is typical of sunlight at about 9.30 - 10.00am in the tropics, and safe enough.... 300 ÂµW/cmÂ² of UVB from some lamps would contain far too much shorter-wavelength UVB, and could even be hazardous for delicate eyes and skin.
> 
> The Solarmeter 6.5 is designed to respond more strongly to the shorter wavelength UVB (by a filter selectively reducing the longer wavelength UVB that reaches the sensor) its readings from lamps and from the sun are much better correlated.
> So it is possible to "match" lamp and sunlight readings and be fairly certain that with a good quality lamp, the UV Index you are reading at the tortoise's basking level isn't far off the same "strength" as sunlight giving you the same reading.
> 
> Lots of people have asked me if there's a simple formula for converting a UVB reading (ÂµW/cmÂ²) from a 6.2 meter into a UV Index reading.
> I wish there was! But because each brand of lamp has a slightly different spectrum, and "new improved" products will doubtless have new spectra too, it's an everlasting game. The only way to do it is to take sets of readings from a lamp, at the same distance, from both meters and plot a graph, from which you can get what's known as a regression formula... (a conversion formula).
> Here are some samples, i.e., conversion formulas I've worked out for some lamps I've tested in the last three or four years, using my pair of Solarmeters. You're welcome to use these formulae but please bear in mind that there's no way I can be certain that your lamps are exactly the same as mine; and I only did the calculation on a tiny sample of lamps. So it's not really more than an estimate... (If anyone has 2 meters and some lamps, and wants to set to work plotting some more... please do! ï¿¼ )
> 
> So: To get the approximate UV Index from a Solarmeter 6.2 reading, divide the Solarmeter 6.2 reading by the following numbers:
> 
> For a ZooMed Reptisun 5.0 or an Arcadia D3 6%UVB tube: 31.4 (average calculated from 4 lamps)
> For a ZooMed Reptisun 10.0 or an Arcadia D3+ 12%UVB tube: 32.7 (average calculated from 14 lamps)
> For a 100watt ZooMed Powersun : 12.2 (average calculated from 5 lamps)
> For a 125watt ExoTerra Solar Glo: 19.4 (average calculated from 3 lamps)
> For a 160watt ExoTerra Solar Glo: 16.7 (average calculated from 2 lamps)
> For an ExoTerra SunRay Metal Halide lamp: 36.6 (average calculated from 2 lamps, one 50W and one 70W)
> 
> To find out what the approximate Solarmeter 6.2 reading would be, at a specific UV Index, multiply the numbers by the UV Index you need.
> e.g. if you want a UV Index of 2 under a ZooMed Reptisun 5.0 tube, multiply 31.4 by 2.
> So UVI 2 would read about 63 ÂµW/cmÂ² under a ZooMed Reptisun 5.0 tube....
> .....ok?
> 
> For the sun, it's really complicated because it changes depending on the height of the sun in the sky. My formula requires a calculator!
> But here are some calculations I made based on a large number of paired solar readings plotted on a graph...
> UVI 1 = 57ÂµW/cmÂ²
> UVI 2 = 108ÂµW/cmÂ²
> UVI 3 = 155ÂµW/cmÂ²
> UVI 7 = 301ÂµW/cmÂ²
> UVI 12 = 437ÂµW/cmÂ²
> UVI 15 = 521ÂµW/cmÂ²
> 
> For example.... suppose I wanted to create a basking zone with a maximum UVI of 3. This is like early morning sunshine about 8.30am in the tropics.
> If I was measuring sunlight the Solarmeter 6.2 might read about 150 ÂµW/cmÂ².
> To match that, I would need approximately:
> 98 ÂµW/cmÂ² with a ZooMed Reptisun 10.0 (3 x 32.7)
> 37 ÂµW/cmÂ² with a 100watt ZooMed Powersun (3 x 12.2)
> 
> Does this make sense to anyone or have you all lost the will to live ï¿¼
> 
> 
> 
> 
> Yes, this is what the Solarmeter 6.2 excels in. Take measurements always at the same distance from the lamp, about once a month and you will be able to see how the UVB gradually declines with age.
> In the first month, most lamps lose quite a lot, but after that the output from a good quality lamp of most types remains quite good for about a full year, only declining quite slowly... It's usual to replace a lamp when it's lost 50% of the UVB it had at first. With some types, e.g., ones that don't put out a lot of heat, you can keep the basking zone UVB the same over the year by lowering the lamp a little, as necessary, as its output falls.
> By taking monthly readings you may discover that some good quality bulbs will keep going for well over a year, without needing changing.
> Or when they are getting a bit low for a sun-basking species, you can use them over a shade-dweller - people can sometimes get 2 or even 3 years of life out of a good lamp in this way.
> 
> Best wishes,
> Frances
Click to expand...


Thank you for the tips, I am sure that would help raising the temps. After playing with the setup further I see a major limitation: The distance of 10 inches allows for only one 6% tube. For an enclosure of my size the UVB basking area is a bit narrow (since the tube is oriented perpendicular to the long axis of the enclosure, see pic). The UVB basking area produced is even smaller than the one my mvb makes.

I guess that this would be great if the tubes would cover a greater surface in my enclosure but the glass covers make this diffecult.


----------



## mikeh

What are you figuring for UVB width coverage of the tube. Even if the tort sits few inches to either side of the tube its still getting UVB, even though the UV index will be slightly lower. 

You can also use Zoomed T5HO 5% which has slightly lower UVB output. 
If two tubes are placed in the outer positions of the fixture they should be spaced about 10" apart. This will create higher UV index where their range overlaps directly in the middle, and only slightly higher index on the sides, but the combined UVB is coming from different angles. Now if the tubes are placed directly next to each other, yes the UVB will be much higher. Finally, raising the fixture one more inch will reduce UVB further, but you would have to tweak getting the temps up.

Just a note. I have an 8 month old leopard under Arcadia 12% at 12" distance. He loves spending time (4-7 hours a day) directly under the bulb despite plenty of space elsewhere and is fine.


You could also experiment with taking the reflector out which will reduce the overall UVB output, but I am not sure by how much and what effect will that have on the temps. and ballast which is placed behind the reflector.


----------

