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.

Over 5000 lumens sq. ft./53750 lumens sq. m. = Optimal growth. Dense growth in all stages.

So, in the "potential" setup that i have going, i have 17200 Lumen's going onto one plant. Will this be enough for my baby? She will be 3ft tall at the end of her life i suspect. Does that mean i need 15k lumens to be well off with her? or can i take down some lightsand save some energy? Also my lamps are 6-4 inches away from leaves, the maxium lumen absorbtion.

It just seems to me that she's not growing fast enough. a month in and we're at 1 foot. i don't think its the soil, or the nutes. It gets plenty of fresh air, constant air flow round it. just wondering if it could be the lights, i dont know where to look after that. Half are 2700k spectrum, other half are 6500k.
casual Reviewed by casual 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