Most commercial LEDs use 460-470nm blue due to cost savings. The most efficient photosynthetic response is at 445nm and 420nm (which is even more expensive unles you use T5 actinic or dual actinic bulbs). Note that the aquarium market always leads the indoor growing market and they are using 445-455nm.

If you are on a budget, use 460-470nm. If you want the best possible go 445nm.
RackitMan Reviewed by RackitMan on . Checking over my DIY LED plan Hello, i am un-hijacking alohamahalo's thread http://boards.cannabis.com/indoor-lighting/193947-help-home-made-led-lights.html and starting a new one here. I plan to make three units, 2 -50w units(roughly) and 1 40w unit(roughly). utilizing LEDengin 5w 660nm for the 40w and a combo of 5w 460 and 660 for the veg lights. Plan is to use {http://reefledlights.com/shop/mean-well-lpc-60-1050} (mean well lpc 60-1050) to run the emitters. I'm finding out at the moment whether or not i have i Rating: 5