Repti-Sun UVB - Is there such thing as "too" much?

Hey there,

So I've just picked up a rankin dragon ("miniature bearded dragon"), their requirements are relatively the same as bearded dragons however they stay quite small. They eat the same foods, require the EXACT SAME lighting, but they love water. He's in a tank that is 1' tall, 3' across, and 1.5' deep as they don't require a huge setup, but still a decent amount of space. I very much understand the importance of UVB and how these guys absolutely need it. I'm also aware that the right type of UVB bulb is just as important. I already had everything I needed for this guy when I picked him up however I'm wondering if the UBV bulb I have may be too strong for him? With all my other bearded dragons I have always just mounted their Repti-Sun T5 HO 10.0 UVB right in the tank with them, however my beardie tanks are double the height of the Rankin tank. Would it be okay/safe to mount a Repti-Sun T5 HO 10.0 UVB light in the tank with it only being 1' foot tall? Or maybe I should consider a different Repti-Sun that isnt as strong? The lid of the tank is a screen top which isn't good either because if I set it on top of the screen its going to cut out a crazy amount of UVB, so that's pointless. Maybe just a completely different UVB all together?! Im worried the UVB is going to be too strong in that short tank, I don't want to overdue it on the lil guy either!!

I'm hoping I can use it just so I don't have to buy another one

Thanks in advance

I'd mount it on top. With a reflective fixture it should still provide a good amount of UVB over the basking area from about 10'' or so. If you build a grow light stand you can raise it a bit higher but without a Solarmeter it's tough to say exactly how much UVB is getting through. That's why it's also quite important to provide a gradient. Have the most intense UVB over the basking area but also allow shade areas and some warm areas that are away from the light (to the side, front, or back) so there are plenty of choices. They don't always want intense UVB so they'll retreat to a warm (or cool) area around it. I think of it similarly to the way I think about the basking temps. Provide a warm/intense area, a moderate area, and a cooler area. This is why even with a smaller or younger dragon you'll want to have at least enough space to provide some good options.

Taterbug has written some very helpful guides which may provide further info for you about this lighting theory https://sites.google.com/site/thelizardmadness/lighting-guides
https://sites.google.com/site/thelizardmadness/photogradient

I'm not TOO knowledgeable on how much is too much, but I do know there are options to take precautions if you're worried and don't want to spend too much. Make sure your calcium dust doesn't have D3, don't include a reflector hood/aluminum foil on the tube, provide a hide with ample space, and you can maybe even shorten his UVB exposure to 8-10 hours a day (while leaving his heat lamp on for the normal amount of time).
Congrats on your new rankins, by the way! Where'd you get him from? I'm considering getting a little one myself, but they're so rare to come by.

The Reptisun 10.0 T5HO UVB tube is strong enough to sit on top of a mesh screen and still penetrate more than enough UVB light, it within 11" of the main basking spot. I've been using the 10.0 T5HO UVB tubes for years in fixtures with reflectors, and I've had them both on top of the mesh lids of EXO Terra glass tanks and mounted unobstructed inside of custom enclosures. I always center the UVB tube over the main basking spot and right alongside the basking bulb, but I make sure I use a long enough UVB tube that it reaches beyond the basking spot, so that they have the choice of getting very intense UVB light or very weak UVB light, and everything in-between. So as long as your fixture has a deflector and you can get the 10.0 T5HO UVB tube within 11" of his basking spot, you can sit it on top of the mesh lid and it will actually work out very well. If it was a 10.0 T8 tube you'd still have to mount it inside the tank and under the mesh lid, and have it at a distance within 6-8" of his basking spot, regardless of his size. So the bottom line is,as far as UVB light goes, don't treat him any different than you did your regular beardies, he needs the same quality UVB at the same distances, and as long as it's a 10.0 T5HO, the mesh lid can block up to 50% of the UVB and it's still emitting more than enough UVB light to your beardie!

Thank you all for replying! I think what I'm going to do is just place it ontop of his screen for now, as you guys had mentioned. I'll see how that goes, I'll keep an eye on the lil ripper to make sure he's getting what he needs. If I have too I can always buy a T8 10.0 bulb and just mount it in with him.

Savora":mgse9bbz said:

I'm not TOO knowledgeable on how much is too much, but I do know there are options to take precautions if you're worried and don't want to spend too much. Make sure your calcium dust doesn't have D3, don't include a reflector hood/aluminum foil on the tube, provide a hide with ample space, and you can maybe even shorten his UVB exposure to 8-10 hours a day (while leaving his heat lamp on for the normal amount of time).
Congrats on your new rankins, by the way! Where'd you get him from? I'm considering getting a little one myself, but they're so rare to come by.

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Awesome, thanks for your help. I'm located in Ontario, Canada so I got him in Toronto at a reptile convention, however my guy was actually born in Czechoslovakia and shipped over. I'm not sure if you're in the area or not but the company I bought him from is called 'Rare Exotic Pets'. He has a website and is located in Cambridge, Ontario. The guy is also super chill and friendly which is an added bonus.