Opie Yutts: I agree with u, today isnt profitable substitute 600w HPS lamp for leds. Probably in 2-3 years.

But leds setups need far less ventilation than HPS ones, if u design the leds arrays in a way wich convection cooling will be enough. This mean not compacted arrays.

Where leds can be now a good choice is for microgrowers. CFLs and small HID lamps are a lot less efficient than 600w HPSs. Using 30% efficients leds at a reasonable price, wich can be found, in about 3-4 years they paid themselves in energy savings against a 250w or smaller HPSs (i did this calculation for my country, Spain, where we are thinking about a leds group buy).Good leds mounted correctly will have a useful life of 30000h, up to 60000h (not white ones, or led bulbs, or cheap 5mm leds)

Today the weak part of a led grow system is the blue part of the spectrum. Blue leds are still too inefficients and expensive. Valid for experimental purposes, but not for energy savings. Now, for small and microgrowers, the profitable way is combining fluo light (for blue and a bit of the others, ensuring no lackings of certain wavelenghts) and red leds.

I would guess it's best to aim for the highest lumen count. Or does it not matter in LEDs? And whats with the 1 watt leds, would they be a better buy?

I think I might build myself red and white flashlights just to have around for camping an stuff. Red light might be good to have in gorilla growing.]
When talking about leds, is a trade off between initial cost and energy savings.

High power leds are cheaper in terms of output mW/$ and in mounting cost, but they are less efficient than medium and low power ones. Lumileds Luxeon III (or the new K2) have a very good initial price, but they are too inefficients at specs currents, and you may need to use more led watts, with less energy savings. A good compromise is run them below specs current, increasing efficiency and ensuring no heat problems (for leds themselves, not for plants), and avoiding active cooling.

Probably the best relationship between initial cost/efficiency (energy savings) can be found in superflux (piranha) leds, runned at 50mA. And they can be founded in all wavelenghts, while high power leds are usually in the range of 630-635nm peak wavelenghts, valid but less effective than longer wl. In the near future, probably the high power leds achieve enough efficiency and good price to be the best option, but not today.
knna Reviewed by knna on . LED grow lights... input please. Hello guys, I'm exchanging eMails with a representative from a LED company. I asked him if they could produce a custom light for growing, and here's what he told me: Our options are as follow: 940nm, 850nm, 660nm, 630nm, 610nm, 590nm 570nm, 530nm, 510nm, 470nm, 460nm, 400nm and a total of 64 LEDs in the bulb. Rating: 5