most people consider 5000 lumens/sq ft MINIMUM for a worthwhile harvest. it can be done with less, but it's really not worth it.

so what is the area of your grow space/cab? this is important in figuring out if your light is sufficient.

CFLs should be kept within ~1-4" from your canopy top.

i usually veg eight or so plants under 6 x 23W, 1700 lumen, 6500K CFLs and it seems like my plants are bigger than than that at one month.

i've got a batch that i've just started. although it won't help you know i will share in the future for a difinitve answer.

have you checked your roots lately to make sure that they aren't getting snug in that pot?


-shake
headshake Reviewed by headshake on . CFL lumen help pls! so, i was strolling around the forum, i found 2000 lumens sq. ft./21500 lumens sq. m. = Absolute minimum for growth. You won't get much from this, especially after the plant has grown a bit. Not really enough to flower well. 3000 lumens sq. ft./32250 lumens sq. m. = Pretty Good growth. Enough light for the entire light cycle, although your yields may be lower. 4000 lumens sq. ft./43000 lumens sq. m. = Very good growth. Once you pass around 3500, growth rate and ability goes up fast. Rating: 5