6 inches from the surface...? 8 bulb...??? have fun watching your fancy mushrooms melt, and acans bleach... LOL....
if you go to growers, wholesale and some LFS, they have their ati lights way up on their tanks... 3 feet above their water level... went to the fragBQ yesterday, and liz/jorge have their T5 way up in the air... growing corals like crazy.. same goes for two guys corals... and amazing aquariums and reefs...