Hey guys,

I am fascinated by the whole subject of LED grows. I've been reading SnSstealth's log, and my theory is that the reason why he has been successful where others have met with such difficulty is this: Lumens.

Most of the products out there marketed as "LED Grow Lights" have no light output ratings at all. Most of them are also garbage.

Please bear with me on this post, I know its pretty long, but I am going somewhere with it

I wish the Procyon 100's used had a lumen rating. It would make comparisons and calculations so much simpler. Because I don't know exactly how much current is driving each of the Cree X-lamps, I can only guess at the light output. Based on their specs (as available from the manufacturer) they put out anywhere from 80 to 200 lumens, depending on how much current is used to drive them.

If one assumes an average value of 140 lumens / lamp that gives a total output for a single Procyon 100 = 140 * 56 = 7,840 lumens. Call it 8,000 lumens to simplify math. My guess is that the true value is no less than 6,000, and no more than 10,000.

Now, given SnSstealth's 8*2 = 16 square feet grow room we have seen that 3 * 8,000 = 24,000 lumens seems to be adequate for that area. That gives us an average of 24,000 / 16 = 1,500 lumens/ square foot.

That's where I was going. It looks like 1,500 lumens/sq. ft. is a good baseline for planning a LED lighting system.

Of course that's all assuming that the output is in the right frequencies. Basically I'm saying one needs to have a lighting set-up put out the frequencies, in the right proportions, reaching at least the intensity calculated here.

Does anyone have any critiques or thoughts on this reasoning? And thank you again SnSstealth for providing numbers that I could base my theorizing on!