Guys,

Just blow this off if it has no bearing but two things came to mind from this novice's collected fragments of info on grow lighting.

1. Is that often mentioned rule of thumb applicable to other bulb types where isn't overall wattage supposed to be a significant measure of growing capability?

2. Other thing was the prism effect in nature... suggesting here that in considering a selection of wave lengths you - being more familiar with basic fundamentals than me - could prob refine estimated wave lengths on the basis of calculating differences in angles - seasonal changes - and then finding the true or existing data on the refraction and prismatic effects of the atmosphere - and somehow come by better figures for the wavelengths that way.

Sorry if totally inapplicable tho.

turtle420, did you get the impression that we would be stuck with the round format? Would there be any advantages to rectangular arrays?

Nice find tho, really interesting, given the reduced heat advantages.
All the exhaust/blower $$$ could go back into the lighting but I'd definitely downplay that aspect in discussions with the R&D dudes.

Out.