i am desiging an aquarium hood for my fish tank and have bought a sheet of acrylic and drilled holes in it for the LED's (74 of them!) i am putting in 25 white, 21 UV, 16 blue, 6 green, and 6 red 5mm LED's. i am wanting to drive these without resistors so i was thinking about using a LM317 and wiring it in constant current mode to power them up. i was going to use 1 Vreg for each color so that i can turn off and on each one. i am going to use a 9VDCD wall adapter to power each regulator and wire the LED's in series to the regulator. does anyone see a problem or a more efficient way to acheive what i am trying to do. i will try to post a schematic of my work to help out. thanks for the help.