Too much UVB

[Itszackbreh]

Would doing a combo of a reptisun 10.0 t8 and a 100w mercury vapor bulb be too much? Is there even a thing “too much uva/uvb”?

 

[CooperDragon]

It wouldn't necessarily be too much but it depends on the model and wattage of MVB. As far as too much, they can handle quite a bit of UVB in bursts but since we have them in relatively small spaces it's best (in my opinion) to offer a happy medium of about 3-5 UVI in the basking area. They can take more than that in the wild but can also burrow and hide easily. For that reason, it's also important to create a gradient so there is intense UVB available on the basking area but little to no UVB in other areas in case they want to get away (which they often do).

A T8 with a reflector will produce about 2.5-3 UVI at 6'' when it's new. A MVB can create quite a bit more than that, but they vary a lot between brands and wattages. The downside of using an MVB in a main tank is that the center can be quite intense and then drop off quickly as you move away from the middle of the beam. The beam is narrow so it doesn't allow for even basking the way a longer tube would (wide, even beam of UVB vs a cone). You also need to set a MVB according to it's UVB output (within a range) and can't adjust it's heat output independently. For this reason I prefer using MVBs as portable lights and travel lights while I use tube UVB lights and non UVB emitting basking lights in my main tank.

 

[Drache613]

Moved by Moderator from General to Enclosures

 

[Itszackbreh]

Thank you, very helpful, I didn’t know that about the mvb that they had a small beam of high intense heat then drop off. I had that problem with a halogen I bought for heat.

 

[CooperDragon]

Some halogen bulbs have that too, yes. I've had the best luck with wide beam flood light halogens set a bit further away to give a wide beam. PAR38 and BR40s seem to provide the best spread but the heat output can vary so it takes a bit of trial and error to get it right. I keep them at least 12'' from the basking area or more. For example, my basking light currently sits 25'' above the floor of the tank and provides basking temps in an 18'' diameter with gradient going down from the center.

 

[Itszackbreh]

I’m about to turn an old dresser into a cage for him. So I’m going to have to redo everything and figure out which light wirks. Also I’m switching from a 18” t8 tube to a 24” T5 HO tube in a sun blaster with reflector. I was reading somewhere with T5 HO bulbs you don’t want tongive them the calcium WITH d3 but instead the calcium supplement WITHOUT it. Is this true?

 

[CooperDragon]

It's a bit of gray area, but the T5 bulbs set at an appropriate distance should produce UVB levels similar to natural sunlight so the dragons can synthesize d3 on their own. I use plain calcium supplement for my bugs and also try to offer a wide variety of veges to ensure he gets the nutrients needed.