# Advantage of using separate UVA and UVB lights rather than a combination bulb?



## OT1_ (Jun 18, 2020)

I am currently doing my research with the potential of getting myself a Russian Tortoise and am wondering about lighting.

If you can get all the light you need from a combination bulb, why do most people choose to use separate UVA and UVB lights in their setups?

What are the advantages of using separate bulbs? Is it dependant on the size of the enclosure and to localise the basking area in one part of the enclosure? or are there health/care benefits from the UVA/UVB light coming from separate sources?

Any advice/input appreciated


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## Crush da Baum (Jun 18, 2020)

Well if you are talking about having a separate bulb for basking and UVB it just comes down to effectivity and safety. HO, tube type bulbs are much more effective and safer then others. Compact bulbs have little output on a UV meter and are known to burn and damage their eyes. Using separate bulbs also helps because you are able to distribute UVB through out the enclosure and not just in their basking spot. I am confused what you mean about separate UVA and UVB bulbs. Many UVB bulbs also emit UVA.


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## jaizei (Jun 18, 2020)

OT1_ said:


> I am currently doing my research with the potential of getting myself a Russian Tortoise and am wondering about lighting.
> 
> If you can get all the light you need from a combination bulb, why do most people choose to use separate UVA and UVB lights in their setups?
> 
> ...



Are you using UVA to mean heat? 

There is typically a tradeoff; with MVB, for example, if you adjust the height to optimize the temperature @ the basking spot, the amount of UVB reaching tortoise level is changed. Single bulbs like MVB are also not enough light for the entire enclosure; so if you have to have multiple lights, it's easier to just use separate lights that serve their role without tradeoffs.


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## OT1_ (Jun 18, 2020)

Yes, I've been doing more reading and when I said UVA I should really have said heat and when I said combination I was referring to MVB.

Thanks for the replies, the reasoning seems obvious when you know. More reading required ?


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## Madkins007 (Jul 25, 2020)

Some quick guidelines gleaned over my research: Main point- we are trying to emulate multiple aspects of the sun, and that takes a little work.
- Hot spots and 'focused' UVB bulbs do not allow good, even, full body basking. Tortoise Trust had great thermal images of torts basking in typical set ups and barely getting the needed benefit.
- Basking is about absorbing UVB AND heat- in the wild they cannot just do one. 
- For UVB, use long fluorescent bulbs that cover the habitat as completely and evenly as possible. Because the bulbs are so close, you probably don't need super high wattages.
- Consider using regular incandescent bulbs for additional lighting. They can be set on a timer to start at when dawn would happen for your species, and go off at dusk. This also lets you run your UVB bulbs for a little less time- generally about 3-4 hours less than the others.
- Thermal gradients are good, but the warm area needs to be big enough for the entire tort to rest in without scrunching or anything. This is one reason torts need lots of space.
- Belly heat is important but tricky. It got a bad reputation when hot rocks, etc. would cause burns or injury. Overhead heat, however, really does not warm the substate much below the surface, and it is worse if you use a dampened material or lots of misting. In the warm part of the day, if you lay your hand on the substrate, it should still feel warm after holding it there a few minutes. A flat basking stone or tile is helpful, and I really like warming cables in the substrate for forest species.
- It is REALLY IMPORTANT to offer shade and cooler areas- humid (slightly or very humid depending on species) burrows or hides are great for many species.


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## Tom (Jul 25, 2020)

OT1_ said:


> Yes, I've been doing more reading and when I said UVA I should really have said heat and when I said combination I was referring to MVB.
> 
> Thanks for the replies, the reasoning seems obvious when you know. More reading required ?


There are four elements to heating and lighting:

Basking bulb. I use 65 watt floods from the hardware store. I run them on a timer and adjust the height to get the correct basking temp under them. I also like to use a flat rock of some sort directly under the bulb.
Ambient heat maintenance. I use ceramic heating elements or radiant heat panels set on thermostats to maintain ambient above 80 degrees day and night for tropical species. You'd only need day heat for a temperate species like Testudo or DT.
Light. I use LEDs for this purpose. Something in the 5000-6500K color range will look the best. Most bulbs at the store are in the 2500K range and they look yellowish.
UV. If you can get your tortoise outside for an hour 2 or 3 times a week, you won't need indoor UV. If you want it anyway, get one of the newer HO type fluorescent tubes. Which type will depend on mounting height. 5.0 bulbs make almost no UV. You need a meter to check this: https://www.solarmeter.com/model65.html


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## Tom (Jul 26, 2020)

@OT1_ 

In addition to the lighting info, here is the correct care info for a Russian. Most of what you read and find will be old, incorrect info with lots of contradictions. This is the most current up to date care info reflecting all that we've learned over the last few years:





The Best Way To Raise Any Temperate Species Of Tortoise


I chose the title of this care sheet very carefully. Are there other ways to raise babies and care for adults? Yes. Yes there are, but those ways are not as good. What follows is the BEST way, according to 30 years of research and experimentation with hundreds of babies of many species. What is...




tortoiseforum.org


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## OT1_ (Jul 26, 2020)

Tom said:


> @OT1_
> 
> In addition to the lighting info, here is the correct care info for a Russian. Most of what you read and find will be old, incorrect info with lots of contradictions. This is the most current up to date care info reflecting all that we've learned over the last few years:
> 
> ...



Thanks @Tom , this is all excellent information. Thanks for taking the time.

I've been reading through *this thread, *which talks about UV levels in terms of microwatts. 

The light I have just ordered (Arcadia t5 12% 24w) quotes UV levels in terms of Index ([email protected]", [email protected]", [email protected]")

Are microwatts and Index comparable and do you know of any information regarding ideal UV Index for a Russian?


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## Tom (Jul 26, 2020)

OT1_ said:


> Thanks @Tom , this is all excellent information. Thanks for taking the time.
> 
> I've been reading through *this thread, *which talks about UV levels in terms of microwatts.
> 
> ...


There is much debate and controversy over UV, and little to no scientific study to quantify which species need what levels, and for how long, and at what temperatures, and how it might differ for different sizes and ages, seasons, and how it all relates to diet and supplements.

You can read and study this subject for days on end and still not get a satisfactory answer, and that is partially because MANY strategies work. Here are the main two:
1. Lower levels of UV left on all day. If you want to go with this strategy, set the bulb height to get a UVI reading around 2 or 3.
2. Higher levels of UV to simulate the daily UV spike that happens outside each day. For this strategy set the bulb on a timer for about 3-4 hours mid day, and set the bulb height to get a UVI reading of 5 or 6.

Either method works to prevent MBD. Either method requires shade and hiding areas. Either method works for tortoise that get D3 supplementation, and for tortoises that do or don't get frequent sunning time in a safe outdoor enclosure.


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## jaizei (Jul 26, 2020)

OT1_ said:


> Are microwatts and Index comparable and do you know of any information regarding ideal UV Index for a Russian?



You can't directly compare microwatts and UVI because lower wavelength UVB is more "intense". 100 µW/cm² from a lamp could be 2 UVI or 10 UVI. 

Nowadays, microwatts (6.2 meter) is mostly used when/if someone is testing bulbs or tracking loss of UVB production over time.


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