Hey Turbo,
What size tank are yours on? Depth?
I am putting 3 of the new 48" retro kits on my 135 tank with 3 10K and 3 actinic bulbss. I wanted to leave a dim area at one end of the tank (hence the 48" bulds on a 72" tank). My filter is also internal and takes up about 5 inches at one end of the tank.
