depends on a lot of variables, including but not limited to strain, stress, and such. but assuming all grows well, you are looking at a worthy harvest. the main thing is penetration (haha i said penetration) if yo can take care of the heat zone around the bulb and try to keep the light as close to the plant as possible w/o buning you will get you lumens worth. there is a chart around here somewhere on lumens/lights and penetration at certain distances from target zone. otherwise you cab just google it. hope that jelps, happy growing
