well 48-56 leds should be plenty of light, are you lighting up a standard 75 gallon? if so try a bit wider heat sink with an 8-9" width and 3/4 the length of your tank typically optics will help manage your light spill, it just depends on how high you want to hang it and how much penetrating power you want. i wouldn't go the cheapo route with your equipment becuase you will eventually regret it. on a heat sink that size though your can make several "pods" of leds to minimize the disco effect i'd say 6-8 xml nw, 18-24 rb, 4b, 4red, and 8 tv. or something similar i'm going to begin experimenting with multi color led fixtures, i've been granted some support with leds from LEDGROUPBUY.COM so that should help further some r&d. i'd say to be safe run everything on dimmable PWM capable drivers unless you have a reef controller that supports 0-10v dimming. but dont mix driver types stick with all pwm or all 0-10v. be sure to actively cool your fixture once done you don't want heat to build up on your leds its a killer.umm i think thats everything off the top of my head at 7am. if theres anything else your interested in let me know i also design custom fixtures and see things through the full build out. i can offer advice or take the entire project over. just let me know how i can help.
-gabe
BAMF Aquatics
