UVB lighting debate

Reptilelady

New member
Hello everyone,
I know leopard geckos are nocturnal/active during dusk/dawn/twilight hours but I have seen some YouTube videos people having UVB lighting for their leopard geckos. I was wondering if anyone here supplies this type of lighting for their Leo's "Arcadia 8 watt MINI UV light Kit". Would like to hear your thoughts and discussion on this hot topic of debate :D
 

Elizabeth Freer

Active member
UVB lighting works well for leos in enclosures at least 30 inches long.

In a 10 gallon there's really not enough space.
 
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lilacdragon

New member
Hi, ReptileLady.

Yes, I keep all my leopard geckos with UVB lighting. I've done this since 2005. Before that, I had a succession of chronic health problems with the ones I had back then, and infertile eggs and some babies that died just before hatching. But once I gave them all low-level UVB they never looked back. My oldest died aged 19, but I still have three of those from that time, now aged nearly 15, 13yr 9mths and 11yr 6mths old, all in perfect health, and four of their babies.
Leopard geckos are not strictly nocturnal; they are cathemeral (can be active at any time of day) although their main activity period is around dusk and early in the night. There is, as far as I know, only one semi-serious study of these in the wild in Afghanistan, but there are also plenty of anecdotal reports of people seeing them out in the daytime. In captivity they often come out briefly during the day - mine certainly do, to see what's going on, when I start feeding my day-active lizards, though I only feed the geckos after dark... I have also seen several of mine basking on top of a hide, under their daytime lamps.
There is growing scientific evidence that leopard geckos can utilise UVB for vitamin D3. I know of two studies, one was presented at a conference in the USA, one is as yet unpublished, done in the Netherlands. But there is no reason to doubt it; all studies done to date on lizards have confirmed that they can synthesise vitD3 using UVB. These don't need much though; thin gecko skin is sensitive to UVB and can use small amounts to good effect. Too much could burn the skin, especially albino and hypo morphs. The brown and black pigments shield skin and eyes from "sunburn" damage, and those without it, like pale-skinned humans, are prone to burn easily.
 

lilacdragon

New member
The Arcadia 8 watt MINI UV light Kit 2.4% UVB is an extremely low-level source of UVB. It's ideal for use in very small vivariums or those with very shallow depth, even inside tubs for snakes. For shade-dwellers with low UVB requirements the max UV Index you need is round about UVI 0.5 - 1.0. You can get UVI 0.5 at a distance of only 4 inches away from the Mini UV 2.4% Kit when the reflector is fitted. So I think it's use is very limited for a leopard gecko in an ordinary viv, where even if he climbs to the top of his hides, is still 8 - 10 inches below the tube.
I use Arcadia T8 (1" diameter tube) Euro Range 5%UVB, or T8 ZooMed Reptisun 5.0 or Arcadia T8 D3 6%UVB tubes, with no reflectors, about 8 - 10 inches above them. (No mesh between tube and gecko). This gives me about UVI 0.5 at gecko closest point. The tubes are on throughout the daylight hours. If they come out during the day, or leave their tails sticking out of their hides, etc., they are getting a little UVB every time they do it. Seems to work well for them.
They also have calcium carbonate powder (no added D3) in small dishes in each viv. And I dust every other feed of livefood with a very small amount of multivitamin/ mineral powder with D3.
 

acpart

Active member
The Arcadia 8 watt MINI UV light Kit 2.4% UVB is an extremely low-level source of UVB. It's ideal for use in very small vivariums or those with very shallow depth, even inside tubs for snakes. For shade-dwellers with low UVB requirements the max UV Index you need is round about UVI 0.5 - 1.0. You can get UVI 0.5 at a distance of only 4 inches away from the Mini UV 2.4% Kit when the reflector is fitted. So I think it's use is very limited for a leopard gecko in an ordinary viv, where even if he climbs to the top of his hides, is still 8 - 10 inches below the tube.
I use Arcadia T8 (1" diameter tube) Euro Range 5%UVB, or T8 ZooMed Reptisun 5.0 or Arcadia T8 D3 6%UVB tubes, with no reflectors, about 8 - 10 inches above them. (No mesh between tube and gecko). This gives me about UVI 0.5 at gecko closest point. The tubes are on throughout the daylight hours. If they come out during the day, or leave their tails sticking out of their hides, etc., they are getting a little UVB every time they do it. Seems to work well for them.
They also have calcium carbonate powder (no added D3) in small dishes in each viv. And I dust every other feed of livefood with a very small amount of multivitamin/ mineral powder with D3.

Gecko Time (Gecko Time - a blog about geckos) would love to have an article about "nocturnal" reptiles and UVB if you're up for it. Feel free to contact me via PM if you're interested.

Aliza
 

Elizabeth Freer

Active member
Thanks so much, Frances! Most of us don't have Solarmeters.

Here in the USA it's quite common to use glass enclosures with mesh tops. Here are the most common enclosures complete with cm measurements.

Is it convenient to copy and paste these sizes in order to add your UVB lighting recs for each taking into account a fine mesh top and a medium mesh top?

EF's common 10 gallon glass
20 x 10.25 x 11.75 inches tall =
50.8 x 26 x 29.8 cm tall

EF's 20 gallon long gallon glass
30 x 12.25 x 11.75 inches tall =
76.2 x 31.1 x 29.8 cm tall

Exo Terra Medium Low
24 x 18 x 12 ~ inches tall =
61 x 45.7 x 30.5 ~ cm tall

Exo Terra Large Low
36 x 18 x 12 ~ inches tall =
91.4 x 45.7 x 30.5 ~ cm tall
 
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lilacdragon

New member
Thanks, Elizabeth.
To keep this simple, I'm going to talk about just one type of UVB lamp - the T8 (1" diameter, traditional style) fluorescent tube. Brands which I know, from testing, have reliable output and excellent longevity (at least one full year) are the Arcadia D3 6%UVB range, the Arcadia 5%+ Euro Range and the ZooMed Reptisun 5.0 range.
What's important, when choosing a UV lamp, is not really the size of the tank. All the size determines, is the length of the tube you can use; the little 10-gallon is only 20 inches long, so a 15-inch tube or an 18-inch tube will be the longest possible; all the others can take a 24-inch tube.
They are all approximately 12 inches tall; but what will vary a lot, will be individual ways of setting up the inside of the tank, i.e., the thickness of substrate, the position and height of hides and climbing rocks or branches, and whether there are "backdrops" which the geckos can climb. All these will determine how close the gecko will be to the UVB lamp, and it is this which is one very important thing, in choosing a suitable lamp.
The other most important thing is whether or not your fixture has a reflector, because if you are going to rest the tube on top of your mesh screen top, you need a reflector fitted. Fortunately, there are several brands of fluorescent tube fixtures for T8 tubes which have built-in reflectors, like this: https://www.petmountain.com/product/reptile-hoods/11442-517291/zoo-med-zoo-med-reptisun-t8-terrarium-hood.html
If you buy a DIY-store fixture with no reflector, or a UK-style ballast controller with cables and end-caps, then you'll need to attach a simple clip-on reflector to the tube, like this: http://www.lightyourreptiles.com/miscellaneous-accessories/arcadia-flourescent-lamp-reflectors
The reflector directs all the light from the top of the tube - otherwise wasted - downwards and counteracts the dimming effect of the mesh screen.
(If you have a wooden vivarium with a solid roof, you can hang the tube inside the vivarium, up by the roof, with no reflector at all.)
I will make a little table of examples of the sort of UV levels you'll expect to get, using these tubes in a reflective fixture over a typical ExoTerra or ZooMed Terrarium mesh screen top, at different distances from the screen, in a new post later today. I'll also give you an idea of the range you're aiming for so you can work out what your gecko will get if he is walking on the viv floor, sitting in his hide entrance or climbing up on top of his tallest hide to bask...
 
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lilacdragon

New member
Here is the info I promised...
A leopard gecko, being primarily active at dawn and dusk and only rarely basking, has been put in the Ferguson Zone category "Zone 1 - crepuscular or shade dweller" (see this article in Reptiles Magazine/ so the range of UV Index suggested is from zero in full shade up to UVI 0.7 in the best-lit areas; a maximum of UVI 1.0 at the closest approach would be perfectly safe. So that's our target - a UVI of 0.7 on top of a hide box or rock, with maybe 0.5 on the substrate and a gradient to zero in cool shade and inside a hide box.
Now I tested several T8 tubes: two Arcadia D3 6%UVB, two Arcadia Euro Range 5%+ and a ZooMed Reptisun 5.0. All gave fairly similar readings - low level UVB - so I averaged the lot to get these results:
No reflector, no mesh screen: 6" = UVI 1.0 / 8" = UVI 0.7 / 10" = UVI 0.5 / 12" = UVI 0.4
With reflector, no mesh screen: 6" = UVI 2.0 / 8" = UVI 1.4 / 10" = UVI 1.0 / 12" = UVI 0.8
With reflector, WITH mesh screen: 6" = UVI 1.3 / 8" = UVI 0.9 / 10" = UVI 0.7 / 12" = UVI 0.5

This means that you'll get your target UV between 10 - 12 inches from the lamp to the gecko, when using a reflector fixture over a typical ExoTerra or Reptisun type of screen top. The way that the tube puts out UVB means that only the area right under the middle of the tube will reach these higher figures; the UV tails off to the ends of the tube. So have at least one hide right under the middle of the tube, where the UVB will be strongest if he sits on top about 10 inches below it. At either end of the viv, higher hides or rocks are not going to get as much UV so no problem if they are several inches closer to the mesh screen.

I hope this is useful...
If you try this and your gecko seems to be squinting or avoiding the light, then it may be too strong for him. Raising the tube up further away, or using a thicker mesh may help, but always watch your gecko's response- especially if he's a hypo or albino morph, or has less pigment in the eyes (red eyes) as this makes them much more sensitive to bright light and UV.
 

Elizabeth Freer

Active member
I've boxed in quotes from your posts to highlight them.

The Arcadia 8 watt MINI UV light Kit 2.4% UVB is an extremely low-level source of UVB. It's ideal for use in very small vivariums or those with very shallow depth, even inside tubs for snakes. For shade-dwellers with low UVB requirements the max UV Index you need is round about UVI 0.5 - 1.0. You can get UVI 0.5 at a distance of only 4 inches away from the Mini UV 2.4% Kit when the reflector is fitted. So I think it's use is very limited for a leopard gecko in an ordinary viv, where even if he climbs to the top of his hides, is still 8 - 10 inches below the tube.

What's important, when choosing a UV lamp, is not really the size of the tank. All the size determines, is the length of the tube you can use; the little 10-gallon is only 20 inches long, so a 15-inch tube or an 18-inch tube will be the longest possible; all the others can take a 24-inch tube.

For leopard geckos in 10 gallon glass tanks with mesh tops WITH or WITHOUT reflectors in UVB fixtures what do you comfortably recommend? I hesitate to suggest either a 15 or an 18 inch tube on a 20 inch long tank, because it seems like there would be insufficient space for a leo to be out and about without dodging the UVB rays.
  • I read online that a "blanket" of UVB is better than a "spot" of UVB.
  • It's good to know that the center of Arcadia & Zoo Med T8 UVB tubes produces more UVB than the ends do.
  • My UVB experience has been solely using Zoo Med's Reptisun T8 5.0 tubes in Slimline fixtures (through 1/8 inch grid mesh WITH reflectors) for 4 Phelsuma barbouri. Phelsuma barbouri require horizontal setups. I've had 2 of these 4 Phelsuma for about 13 years. They totally depend upon UVB for D3 synthesis. I don't use any supplemental D3 powder with them, just a multivitamin without D3.
Which multivitamin/multimineral powder with D3 do you use for your leos? Is that D3 just for "insurance" in case the UVB rays don't reach them?
 
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lilacdragon

New member
For leopard geckos in 10 gallon glass tanks with mesh tops WITH or WITHOUT reflectors in UVB fixtures what do you comfortably recommend? I hesitate to suggest either a 15 or an 18 inch tube on a 20 inch long tank, because it seems like there would be insufficient space for a leo to be out and about without dodging the UVB rays.
Leopard gecko vivs need lots of hides; in the wild these little guys live in and around rocky outcrops and in places where humans live, they use old stone walls, hiding in gaps between the stones. If you've got three or four hides and sheltered areas right across the bottom of your tank then a 15" or 18" tube will produce a gentle "UVB in the shade" level (which is what UVI less than 2 is, anyway) across unshaded areas, that's perfectly fine. Your gecko will spend most of his time in one hide or another during the day when the UV is on, and get a little whenever he moves from one hide to another, or comes out briefly to bask.
A 10-gallon is rather small for an adult leopard gecko? I'd suggest at least a 2ft minimum length.. but if you create multiple hides then you do increase the area he can roam in, because there's "up on top" and "underneath" each hide.
 

lilacdragon

New member
BA7ArcadiaD3T8.jpg This chart is a diagram of the UV Index measured under a 2ft Arcadia T8 tube with NO reflector and NO mesh. It shows how the UV "beam" spreads out under the tube and tapers off towards each end.
A reflector approximately doubles the UVI at any point. A mesh screen top reduces it by about 35%.
 

lilacdragon

New member
Which multivitamin/multimineral powder with D3 do you use for your leos? Is that D3 just for "insurance" in case the UVB rays don't reach them?
The amount of D3 in most brands of multivitamin/mineral powders is very low. I regard it as part of their normal supplement added to commercially-reared insects, because these cannot provide as varied a diet as the wide variety of things they'd eat in the wild. I've used several different supplements over the years. One called Nutrobal is the one I use most.
 

LilBobbyD

New member
The Arcadia 8 watt MINI UV light Kit 2.4% UVB is an extremely low-level source of UVB. You can get UVI 0.5 at a distance of only 4 inches away from the Mini UV 2.4% Kit when the reflector is fitted.

Dr. Baines, Thanks so much for all you information in this thread. You do have me a little worried as I have been using the 2.4% uvb bulb for my leo for a few months now. Is that UVI rating from your own research? I have been trying to find an iso-radiance chart or equivalent for that bulb all morning now. Really wish I could get my hands on a radiometer.
 

lilacdragon

New member
Hi, LilBobbyD.
Please don't be too worried. By providing UVB from the little 8-watt Arcadia mini-UVB kit, you are already doing more than most leopard gecko keepers in the UK today. Your gecko is now getting a little of his vitamin D3 by utilising the small amount of UVB reaching him, in addition to the vitamin D3 you are giving him in the calcium + vitamin D3 powder I'm assuming you're using to dust his livefood. Keep providing both the powder and the lamp. He'll be fine.
You haven't said how close your gecko can get to the tube. If he can't get to about 4-6 inches of it, when he's as close as he can get (eg. sitting on top of a hide box) then when you replace the lamp, you might like to consider upgrading to a standard T8 tube such as a ZooMed Reptisun 5.0 or an Arcadia D3 6%UVB tube. If he's in a 2ft or 3ft tank, you won't need more than the small 15-watt, 18-inch tube as it only needs to illuminate about half to two-thirds of his tank.
Yes, to answer your question, the readings I reported were from my own data, and no, there isn't an iso-irradiance chart on the internet anywhere, because I haven't had time to draw one... sorry..
Best wishes,
Frances
 

LilBobbyD

New member
I've been giving him calcium with D3 monthly. I guess I should switch to at least bi-monthly. The rest of the time he gets calcium and vitamins without D3.

He could get within ~4 inches if he climbed on his hide. I've never seen him attempt to get that close though. He usually just sticks his butt out of his hide or lays in a corner under his hammock and some fake plants, so he is partially shaded, when he is catching rays. He usually spends the majority of the day in a hide though, at least from what the wife and I have observed. We are at work most of the time his light is on though.

You're sure right about the iso-radiance charts. I wasn't able to find anyone else putting that type of research online. I'm surprised the light manufactures don't publish information like that. It would sure help their customers purchase the right lights for their setup and animal.
 
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