| Daniel - I think you and I are thinking the same thing - note you said 790 and I said "just under 800". And yes, to maximize the usefullness of these lights they will need to be as close to the plants as possible - inches preferably. My setup has three shelves of four fluorescents at 3000 lumens each tube. I get 1000 footcandles AT THE BULB and as you have noted rapidly decrease from there. Only a couple inches away and I drop to 7-800. Phals under these lights 14-16 hours a day seem to do wonderfully - but as you suggest - just inches away. mike |