So if he can get to the 8 inches from the UVB when hes under his basking lamp he should be good -- you wouldnt need to change it out - so hes getting both lights if hes under the basking light? and at 8 inches? The forum recommends that full length UVB bulbs not be installed --- usually 2/3 of the tank is recommended -- I have a 4x2x2 and only use a 24" in my tank --- it is a T 5 w/ a Arcadia bulb 14% inside the tank and appox 13 inches from his basking spot-- he seems to be ok w/ the distance as that is a good strong bulb-- keep an eye on his behavior ---
Karrie