I tried searching for it but cant seem to find it. But one of the forums that OR was a sponsor they had said that you should work your way up to a combined 110-120 percent on both channels. I have 2 T247's over a 48" tank thats 21" deep I run blues for 12 hours and whites for 10 hours. I started low and worked up to 65 blue and 45 white for a combined 110 and all my corals to include SPS grow like crazy. When I get something new I have to put it in a shady spot and work it out into the light so I dont bleach it.