Help with UVB lighting for a Hermann's tortoise

[Moonrabbit]

I have a 5-year-old male Hermann's tortoise. To date, based on information I gathered online several years ago, I have been using a 17W T8 UVB 10 lamp (Zoo Med). I learned this week that T8 bulbs should be switched every 6 months as they cease producing UVB radiation after that time. Reading online, it seems that most people are now recommending use of T5 lamps as they produce UVB up to 12 months. However, I don't think a T5 lamp with similar UVB output would work for my cage setup. The lamp currently sits on top of the cage, projecting through light mesh, about 25 cm above the substrate. Please see the attached picture. At this height, I think most T5 lamps would be too strong.

I see a lot of people now recommend Arcadia lamps. When I look at the Arcadia website for lighting recommendations for Hermann's tortoises with the light placed at 30-40 cm above the substrate, it recommends T8 UVB 12% D3+ Desert or T5 UVB 6% D3 Forest. I need a 24" fixture to span the width of the cage. I can find 24" Arcadia T5 fixtures for sale online but am not seeing any 24" Arcadia T8 fixtures for sale (even on the Arcadia website when Arcadia suggests that a T8 solution can work).

Can anyone point me to a specific lamp and bulb combination that is suitable for my enclosure? It is also unclear to me that the Arcadia T8 UVB 12% D3+ Desert and T5 UVB 6% D3 Forest are fully equivalent. Can anyone point me to the math indicating that the pertinent radiation metric is the same or similar for the two lamps?

Thanks to all and happy holidays.

 

[Tom]

I have a 5-year-old male Hermann's tortoise. To date, based on information I gathered online several years ago, I have been using a 17W T8 UVB 10 lamp (Zoo Med). I learned this week that T8 bulbs should be switched every 6 months as they cease producing UVB radiation after that time. Reading online, it seems that most people are now recommending use of T5 lamps as they produce UVB up to 12 months. However, I don't think a T5 lamp with similar UVB output would work for my cage setup. The lamp currently sits on top of the cage, projecting through light mesh, about 25 cm above the substrate. Please see the attached picture. At this height, I think most T5 lamps would be too strong.

I see a lot of people now recommend Arcadia lamps. When I look at the Arcadia website for lighting recommendations for Hermann's tortoises with the light placed at 30-40 cm above the substrate, it recommends T8 UVB 12% D3+ Desert or T5 UVB 6% D3 Forest. I need a 24" fixture to span the width of the cage. I can find 24" Arcadia T5 fixtures for sale online but am not seeing any 24" Arcadia T8 fixtures for sale (even on the Arcadia website when Arcadia suggests that a T8 solution can work).

Can anyone point me to a specific lamp and bulb combination that is suitable for my enclosure? It is also unclear to me that the Arcadia T8 UVB 12% D3+ Desert and T5 UVB 6% D3 Forest are fully equivalent. Can anyone point me to the math indicating that the pertinent radiation metric is the same or similar for the two lamps?

Thanks to all and happy holidays.

The info about bulbs only lasting 6 months is false, according to my meter, and appears to be a sales tactic to move more bulbs. Get a Solarmeter 6.5 and you'll see what I mean. Without the meter you are just wasting money, and you also don't know if your tortoise is getting enough UV or to much.

The Arcadia 6% HO tube will probably work for you, but I'd put a meter under it to be sure. You might have to rig up a way to raise the light fixture up a bit.

I see some other problems that I'd like to mention in an effort to help you and your tortoise.
1. Your enclosure is far too small for a tortoise this size. You need something 4x8 feet.
2. Those ramped water bowls are not safe. Tortoises regularly flip over in them and some drown. Use a terra cotta saucer sunk into the substrate for food and water instead.
3. Coco chips are not a good substrate for tortoises. Coco coir can work, but the chips are an impaction hazard and hard to walk on. I like the chips for some lizards and some snakes, but not for tortoises.
4. Your tortoise is pyramiding. This is caused by growth in conditions that are too dry. The open top on your enclosure lets all the heat and humidity out. Some bulbs will contribute to this too. Are you using one of those "intense" spot bulbs sold in pet stores? Those cause "intense" pyramiding. You need a flood bulb, and you need to be able to adjust the height to get the correct basking temperature under it.

More here, and there is a temperate species care sheet and heating/lighting breakdown near the bottom. This will cover everything discussed here and more:

Info For New People. Please Read This First.

Hello and welcome to tortoiseforum.org! We are all glad you are here! There is no other forum like this anywhere. We have tens of thousands of members from all over the world ranging from kids with their first tortoise to people who have been breeding and keeping high end tortoises since the...

tortoiseforum.org

 

[Alex and the Redfoot]

Hello!
1. Lifespan of T5 and T8 lamps in terms of UV level degradation, I believe, is almost the same. Arcadia states 12-month lifespan both for T5 and T8 lamps. Many lamps work longer than this. Due to higher UV output of T5 lamps they give useful UVB level for longer period and with adjusting height and adding/removing reflector you can use T5 lamp for years, but I wouldn't do this without a radiometer (Solarmeter 6.5).

2. To use Arcadia T8 lamps you don't need an Arcadia fixture. Other T8 fixture with similar wattage will work. Same for T5HO lamps (you can get a suitable fixture from a hardware store).

3. Percentage on lamp labels shows how much of lamps emitted radiation is in UV-B spectre band. So, to compare the output you need to take lamp wattage, take percent and divide by lamp surface area. Long story short, UV-B output between T5 6% and T8 12% is very close, however T5 lamp gives significantly more visible light and UV-A.

A few general points on UVB lamps:
1. You can use them just 3-4 hours a day, to mimic natural UV exposure under sunlight.
2. Having a fixture and lamp along whole enclosure is not necessary. Providing UV at the basking area is sufficient and more natural.

Right now, I would keep using T8 lamps (since you have a fixture and T8 lamps are generally cheaper) and invest this money to get a Solarmeter 6.5 (to save on lamp replacements and to be sure about setup correctness).

--
Agh... Tom was first and his answer is far more complete You may skip my reply entirely

 

[Moonrabbit]

The info about bulbs only lasting 6 months is false, according to my meter, and appears to be a sales tactic to move more bulbs. Get a Solarmeter 6.5 and you'll see what I mean. Without the meter you are just wasting money, and you also don't know if your tortoise is getting enough UV or to much.

The Arcadia 6% HO tube will probably work for you, but I'd put a meter under it to be sure. You might have to rig up a way to raise the light fixture up a bit.

I see some other problems that I'd like to mention in an effort to help you and your tortoise.
1. Your enclosure is far too small for a tortoise this size. You need something 4x8 feet.
2. Those ramped water bowls are not safe. Tortoises regularly flip over in them and some drown. Use a terra cotta saucer sunk into the substrate for food and water instead.
3. Coco chips are not a good substrate for tortoises. Coco coir can work, but the chips are an impaction hazard and hard to walk on. I like the chips for some lizards and some snakes, but not for tortoises.
4. Your tortoise is pyramiding. This is caused by growth in conditions that are too dry. The open top on your enclosure lets all the heat and humidity out. Some bulbs will contribute to this too. Are you using one of those "intense" spot bulbs sold in pet stores? Those cause "intense" pyramiding. You need a flood bulb, and you need to be able to adjust the height to get the correct basking temperature under it.

More here, and there is a temperate species care sheet and heating/lighting breakdown near the bottom. This will cover everything discussed here and more:

https://tortoiseforum.org/threads/info-for-new-people-please-read-this-first.202363/[/

Thanks so much for the detailed information. Some thoughts (and further questions) based on your comments.

1. The pyramiding is very concerning. I took my tortoise to a herpetologist for a beak trim earlier this week, and she didn't mention this. When the tortoise was a baby, I used a humidifier that had a hose that could extend into the tank. I guess I'll pull that out and try it again. What humidity should I be shooting for with a 5-year-old tortoise? The humidity runs pretty low currently with all the lights and heaters.

2. I have a basking lamp in one of the larger domes. The other two domes contain CHEs. The smaller CHE is on all the time. The larger CHE and basking light are on timers (light during day and CHE during night). The UVB light is on the same timer.

I am not certain how a flood bulb would be different from the basking light (Zoo Med, I believe). I saw a link to the following in another post on this forum:

https://www.amazon.com/gp/product/B002JH0YOY/?tag=exoticpetnetw-20

Is this something you would recommend? This appears to be an incandescent bulb. These are illegal in some states, and I believe they are to be soon illegal nationwide.

3. Regarding the UVB light, I'll look into the solarmeter. Will try to get the Arcadia Pro T5 fixture with the 6% bulb. Am looking into risers that would elevate the lamp up to another 4" or so.

4. Will address the substrate and water dish as suggested.

5. Regarding the cage size, this is a problem. We really do not have the space for an 8' cage, and I wouldn't even know where to get one. My wife would push back hard on getting a larger cage.

 

[Alex and the Redfoot]

1. To keep humidity high enough you can simply cover the mesh with an aluminium foil, leaving no holes around lamp fixtures. Then pour some water in the corners to wet lower substrate layers. Usually it's enough to do that once a week. Target humidity is 50-60%.

2. CHEs should be run on a thermostat, not on timers.

For a basking zone flood incandescent lamps work best: they don't dry out shell, give beam wide enough for tortoise to fit under, don't tie together UVB exposure and basking time.

You are right about the ban of the incandescent lamps, however some of the reptile basking lamps are, in fact, incandescent ones (like Arcadia Solar Basking Floodlight) and that's a legal way to get them. Halogen lamps, mercury vapour bulbs (MVB) and incandescent spot lamps are too drying for growth areas of tortoise shell and that leads to pyramiding. Maybe one you have from ZooMed is of a correct type: if you have packaging or label photo we can check.

5. Some keepers build "double-decker" enclosures with a ramp between levels. Maybe you can make an L-shaped one. Here is an overview post on Reddit by one of the forum members (I hope it will be posted and pinned here soon):

https://www.reddit.com/r/tortoise/comments/18jg1bw

 

[Moonrabbit]

1. To keep humidity high enough you can simply cover the mesh with an aluminium foil, leaving no holes around lamp fixtures. Then pour some water in the corners to wet lower substrate layers. Usually it's enough to do that once a week. Target humidity is 50-60%.

2. CHEs should be run on a thermostat, not on timers.

For a basking zone flood incandescent lamps work best: they don't dry out shell, give beam wide enough for tortoise to fit under, don't tie together UVB exposure and basking time.

You are right about the ban of the incandescent lamps, however some of the reptile basking lamps are, in fact, incandescent ones (like Arcadia Solar Basking Floodlight) and that's a legal way to get them. Halogen lamps, mercury vapour bulbs (MVB) and incandescent spot lamps are too drying for growth areas of tortoise shell and that leads to pyramiding. Maybe one you have from ZooMed is of a correct type: if you have packaging or label photo we can check.

5. Some keepers build "double-decker" enclosures with a ramp between levels. Maybe you can make an L-shaped one. Here is an overview post on Reddit by one of the forum members (I hope it will be posted and pinned here soon):

https://www.reddit.com/r/tortoise/comments/18jg1bw

I believe it's an Exo-Terra 150W basking light.

Will place the foil over the screen as you suggest. Will also look into double decker cage. I have another tortoise box close to the same size as the one I am using now. Moved to the current one as it had windows. Wife said the other one was like a coffin. Could probably stack them if I cut holes and build a ramp the tortoise can get up.

 

[Tom]

Thanks so much for the detailed information. Some thoughts (and further questions) based on your comments.

1. The pyramiding is very concerning. I took my tortoise to a herpetologist for a beak trim earlier this week, and she didn't mention this. When the tortoise was a baby, I used a humidifier that had a hose that could extend into the tank. I guess I'll pull that out and try it again. What humidity should I be shooting for with a 5-year-old tortoise? The humidity runs pretty low currently with all the lights and heaters.

2. I have a basking lamp in one of the larger domes. The other two domes contain CHEs. The smaller CHE is on all the time. The larger CHE and basking light are on timers (light during day and CHE during night). The UVB light is on the same timer.

I am not certain how a flood bulb would be different from the basking light (Zoo Med, I believe). I saw a link to the following in another post on this forum:

https://www.amazon.com/gp/product/B002JH0YOY/?tag=exoticpetnetw-20

Is this something you would recommend? This appears to be an incandescent bulb. These are illegal in some states, and I believe they are to be soon illegal nationwide.

3. Regarding the UVB light, I'll look into the solarmeter. Will try to get the Arcadia Pro T5 fixture with the 6% bulb. Am looking into risers that would elevate the lamp up to another 4" or so.

4. Will address the substrate and water dish as suggested.

5. Regarding the cage size, this is a problem. We really do not have the space for an 8' cage, and I wouldn't even know where to get one. My wife would push back hard on getting a larger cage.

1. A "herpetologist"? Everyone reading this is a herpetologist. You have someone out your way selling their services as a herpetologist? That just strikes me as odd.

Beak trims should not be needed. Something is wrong somewhere if a beak trim was needed.

Humidifiers should never be blowing directly into a tortoise enclosure. The way to maintain humidity is to use a closed chamber. Open topped enclosures don't work very well, as you have noted.

For an already smooth tortoise that had a little growing left to do, I'd shoot for 50-70% humidity. For a tortoise that is already pyramiding I'd keep it closer to 80% with 100% humidity in the humid hide.

2. Basking lamp on a timer, CHEs on a thermostat. If you want a drop in temp for night time, you can set your two CHEs on a different thermostats and run them through timers. Maybe 75-80 for daytime and 65 for night.

Spot bulbs concentrate too much IR-A into to small of an area. Flood bulbs spread it out more.

Flood bulbs are not illegal to possess. They are illegal to sell in some states. Just get them where you can. Stockpile them if you can find a good source.

5. Tortoises need lots of space. It doesn't matter how your wife feels about it. Cramping them into small quarters can cause health problems and its just plain cruel. I'm not accusing you of cruelty, but we seen large tortoises in little small tanks, and that is cruel. There are lots of reptile pets that do fine in smaller enclosures. Tortoises just aren't one of them.

I hope these suggestions will help.

 

[Alex and the Redfoot]

I believe it's an Exo-Terra 150W basking light.

Will place the foil over the screen as you suggest. Will also look into double decker cage. I have another tortoise box close to the same size as the one I am using now. Moved to the current one as it had windows. Wife said the other one was like a coffin. Could probably stack them if I cut holes and build a ramp the tortoise can get up.

1. This lamps perhaps, is too dissicating. Flood lamps have beam angle close to 120 degrees, and spotlights like this can be as narrow as 40. ExoTerra has also Daylight Basking lamps (incandescent, R20/R30 type), they are suitable for a basking zone. Also, at height of 25cm, 150W directed lamps are usually an overkill, but only thermometer tells the story.

2. Please, be careful after covering enclosure with foil - temperatures might ramp up quickly. Perhaps you will need to turn off "daytime" CHE. That's why thermostats are a must.

3. I hope you'll succeed with a double-decker. One thing not to be overlooked - you will need an easy access to both floors and areas for cleaning and maintenance. "Staircase-style" may work better for this (and a bit easier to mount lights and heating).

 

[Moonrabbit]

1. This lamps perhaps, is too dissicating. Flood lamps have beam angle close to 120 degrees, and spotlights like this can be as narrow as 40. ExoTerra has also Daylight Basking lamps (incandescent, R20/R30 type), they are suitable for a basking zone. Also, at height of 25cm, 150W directed lamps are usually an overkill, but only thermometer tells the story.

2. Please, be careful after covering enclosure with foil - temperatures might ramp up quickly. Perhaps you will need to turn off "daytime" CHE. That's why thermostats are a must.

3. I hope you'll succeed with a double-decker. One thing not to be overlooked - you will need an easy access to both floors and areas for cleaning and maintenance. "Staircase-style" may work better for this (and a bit easier to mount lights and heating).

What are your (or others') thoughts on this enclosure?

https://www.aliexpress.us/item/3256805851486711.html?src=google&aff_fcid=86cf6c5b89c74ceda1fc1a875e534fe0-1703348325201-03415-UneMJZVf&aff_fsk=UneMJZVf&aff_platform=aaf&sk=UneMJZVf&aff_trace_key=86cf6c5b89c74ceda1fc1a875e534fe0-1703348325201-03415-UneMJZVf&terminal_id=bc5de62edd9f4249b7aa43a09aa9133a&afSmartRedirect=y&gatewayAdapt=glo2usa

The footprint of this is a bit bigger than what I have currently, and it would offer some additional space on second level. I suspect this would be a pain to clean, and the slanted mesh covering and gable roof would make heating and lighting more difficult. While I've seen lots of stands for heat lamps and thermal emitters, I have only found 3D printed risers for UVB lamps. Realistically, I would need something to hang the UVB lamp over the cage.

 

[Alex and the Redfoot]

Hello!
It looks really neat. However it has only 9 sq.ft of usable area. And recommended space is 18-32 sq.ft. for an adult Hermann's... Since you already have two enclosures, maybe buying a third one of almost the same size is not a good idea (and this new is not cheap at all). I understand that lack of room space is not an easy problem to solve (I'm in the same boat actually). Among other options can be heated insulated outdoors shed/greenhouse, other place in the house for the enclosure (under a bunk bed, in the basement and such). Anyway, there is no need to rush now and it's better to carefully plan ahead.

Hanging lights, retaining humidity and temperatures with that kind of enclosure can be done rather easily with a greenhouse top. For regulating UVB light height you can use something simple, like Lego bricks or hang it from greenhouse frame.

 

[Moonrabbit]

Hello!
It looks really neat. However it has only 9 sq.ft of usable area. And recommended space is 18-32 sq.ft. for an adult Hermann's... Since you already have two enclosures, maybe buying a third one of almost the same size is not a good idea (and this new is not cheap at all). I understand that lack of room space is not an easy problem to solve (I'm in the same boat actually). Among other options can be heated insulated outdoors shed/greenhouse, other place in the house for the enclosure (under a bunk bed, in the basement and such). Anyway, there is no need to rush now and it's better to carefully plan ahead.

Hanging lights, retaining humidity and temperatures with that kind of enclosure can be done rather easily with a greenhouse top. For regulating UVB light height you can use something simple, like Lego bricks or hang it from greenhouse frame.

Thanks. Yes, I realized earlier this morning that enclosure would only provide a modicum of extra area. Even if I stacked the two cages I have I'd still only have ~16 sf.

Right now the biggest issue I have is the humidity/pyramiding. I swear the last time I read recommendations for adult tortoises it was 30% humidity. Now I see 60% for adult Hermann's tortoises. I have multiple humidity gauges in the enclosure and have covered the top with foil as someone suggested. I'd like to get a riser to elevate the UVB lamp a bit, but that will work against the humidity since I need an open space for light to get in. Immediately, I'm going to get another timer for the UVB lamp and have it run only 4 hours mid day.

 

[Alex and the Redfoot]

16 sq. ft. is a significant boost from 6-7. It worth the efforts (should be doable relatively easy).

Recommendations from different sources might tell different numbers (and older sources usually advice dry keeping). However, 50-70% is the optimal level. Besides ambient humidity correct heating and lightning sources should be used (wrong ones, like mercury vapour bulbs or deep heat projectors, dry out growing keratine layers).