I read 12" or less was fine?. I had it at 10" from the T5 to the basking branch. I had raised the light to take pics so everything could be seen. It's not possible for the T5 fixture and the basking light to be in the same area with both flushh on top. There would need to be separate areas for ea light. Also the misting head sites on top of the cage so the T5 could not go lower than 6" from the top. To be honest I didn't like the way it looked using rope ratchets hanging, Looked messy to me. I redid the top this is what it look's like now. I hot glued the hose to the side with stress relife cable. I had to put the T5 all the way back sits on top now and move the basking light up front , added another branch under the Basking light and relocate the misting head to front middle. I took Ares out for a min while I was moving stuff. I think it looks like he is gonna be green/Teal.