The 5.0 bulb is basically the same as your T 8 --- so its your choice -- the distance needs to be 6-8 inches from the basking decor directly above it w/ NO obstruction and NO clear plastic cover over the bulb -- if its on take it off please --- take the UVB fixture and place it width wise on the tank take the screen and butt it up against it w/ your basking bulb on top next to it -- when you move him to the bigger enclosure your gonna need the 10.0 bulb -- if you need a pic of the 20 gallon tank like I have described I can post a pic of mine the way I had it set up -- if you need more help please ask --- Tracie is going to haft to look at little dudes leg-- is he moving it at all? I know you said the other one he was using is that correct ? Is he black bearding at all ?
Karrie
Karrie