Hi Major. Do you regularly test the pH of either your soil or your runoff? If not, might be a good idea to do so.
That's one reason why a consistent LED array providing ~400-700
umol PPFD is a much better, more efficient alternative indoors, too...and why it's usually better to use more, lower wattage emitters spread out over a larger area, than trying to push more light out of fewer, high-watt LED arrays, which in effect reproduces many of the negatives we get from traditional point source lighting (and which we're trying to get away from).
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I'd try 1) raising the lights up higher/attenuating their radiance, and/or 2) looking at reducing the mA to your circuit.
Are your drivers dimmable?
Also, do you still have those CFLs in there? Don't need 'em!
Just my $0.02.
Cheers,
-TL
Cheers for all this TL, by the way...if you're still lurking! Very good info. I took your advice on reducing the radiance (no dimmable drivers unfortunately..they're fixed current). I took out the CFLs, and raised the LEDs. It was obviously the right thing to do, because my ladies are doing very well now. I'll use that 40W/ft2 reference figure for future grows!
I have now added the CFLs back, but then my grow space has had to expand to fit my bushy ladies, so it all still works out.
Although I understand your point, that an even spread of light is preferable two point sources, I quite like the penetration that the arrays provide, and I really love the fact that they are each only 5" in diameter. In the confined space of my closet grow, these LEDs are much more flexible than a single panel would be. I can move each around, and raise and lower them independently as required.
If each individual 3W LED in a grow panel could be moved up or down with the canopy then I'd value their even coverage more...but in my current grow I think it would be really hard to light the bottom of my largest plant with a 85W panel of 3W LEDs at a fixed height above it. As it is, I have 2 lights at staggered heights, so the light nearest to the smallest plants' canopy also lights the bottom of the larger plant. (If you know what I mean..I'm probably explaining this badly)
If I get good yield and quality of this grow then I might start building and selling these lights man. I love them because they're so easy to use, mainly because they're so compact and neat. If I can be bothered post-harvest!!
