...but it seems that plants need a coupla spikes in the spectrae... for the red, around 630nm as well as 660nm, and the blue around 450nm as well as 470nm. Trying to remember where I heard it, but for flowering, apparently far red around 720nm is also needed. I'm sure that there are other bits of the spectrum that should be represented, hence most LED manuf's adding some type of white and / or 'amber' at around 610nm...

khyberkitsune and Weezard have mega-experience running and building these things, something I hope to be doing as well before too long