It really depends on how you have the lighting and "furniture" configured. The goal is to create a gradient so a dragon has options. They will move around a lot over the course of the day and choose different temps and different UVB exposures. If you have a UVB tube running the whole length of the tank, it's a good idea to set it forward or backward a bit so you can create a gradient along the depth of the tank. I have mine set up this way. It's also good to provide some shade areas using hides or wood branches etc. The gradient is sometimes easier to establish using a UVB light that is shorter but it can be done either way. Sometimes they want 3-6 UVI to bask under, sometimes they'll sit to the side a bit and get 1 UVI, sometimes they'll want heat but no UVB exposure, etc.
I like to suggest a minimum length of about 24'' so that the spread of UVB is long enough to allow an adult dragon to bask evenly. I suggest the same for basking area temp zones. If they can bask evenly and can move away from the high heat and high UVB as they wish, then they should be in good shape.
Thanks for answering that question----- I have heard it was not good as they cant get away from it - so basically its for more experience owners that would be able to do this --- some people dont even get that they are supposed to even have a UVB --- :shock: ----
Karrie
Yeah first things first, get a UVB light lol :lol: *sigh*. This is how I have mine set up. Darwin can move away from the bulb pretty easily if he wants to and the UVI along the back wall is less than 1. The hides and driftwood produce areas with no UVB exposure and cooler temps. This is not a perfect example by any means, just one possible way of configuring it and an example of how to set a UVB light forward in the tank to create a gradient along the depth.
This is with his usual 34'' T5.
And here's what it looks like with a smaller (24'') T5:
You do want to have a gradient of uv just like you do with heat, but that can be achieved multiple ways.
For instance If you have a tall tank and a tall basking surface, a full length tube could still give you very low levels at the ground level and good levels high up on the basking surface. Or if you had s really deep tank and the bulb spanned the whole length but was up against the back wall, the front of the tank could have a gradient from high to low.
It's just easiest to recommend 3/4 of the tank for the uv as it's a good generalization for most setups. With more detail though (such as the examples I gave) multiple different setups can achieve the same goal of uv gradient.
So mine is set up w/ UVB in front of tank 24" and his basking area is in back of tank w/ a gradient temp - he can sit in multiple places for different heat temps-- the UVB he can sit on top of rock or lean on it sitting up like he normally does-- I am thinking it must be a good set up as he seems healthy other than the fact he eats very little vegies-- which is stubborness --?
Karrie
Some guidance here :
this is generally considered the optimal setup , tube no longer than 3/4 the length of the tank.
If it's like this
Eg tank 24"H x 26"D (front to back)
A picture says a 1000 words and shows everything succinctly and clearly.
It is likely the UV spread from the end of the T5HO will create a low UV zone (perhaps even a zone at very close to zero UV). If the UV tube is more than 12 inches from the cold end of the tank , the UV in the last 8 inches will be very low (near zero). This can be confirmed by looking at the iso-irradiance charts published here http://www.uvguide.co.uk/fluorescenttubereflectortests.htm
that look like this :
If you are stuck with a full length tube, the best option for now is to place it and it's reflector hood in the back top corner and adjust the angle of the dangle so it's "pointing" so the lope of the tube's iso-irradiance UV flux field is directed towards the basking spot while still pointing at the floor of the tank .