I believe the rule of thumb for CFL is 50W Sq Foot. Or 3000 lummes Sq foot preferable 5000
kdspecial Reviewed by kdspecial on . How many plants? I've got a pretty small box (32"x27"x16"). I put in four 42W cfl lamps putting out a total of 10,800 lumens and lined it with mylar. I even got a little computer fan going. I plan on trying three plants and LST them. But I was wondering if I went ahead and tried to put a total of six plants, each in its own 8" pot, would the lumen total be enough to sustain them or would having more plants draw more energy away from the other plants. I really don't plan on doing more than three cause it would Rating: 5