ive been flowering for 4 weeks with a 70 watt metal halide and 4 t-12 florescent 3000k lights seems to work fine it did take a few more days to see the sex on my plants under this lighting tho. you may not be able to see from the pics but 3/4 of the plants are female the last one is still up in the air... If your looking at my set up youll see its 2x3 6 in pots the one in the middle closest to you in the pic (the biggest one) is a definite female. the one directly behind it is still unsure but the other 2 on each end are most likely female (im guessing so because of the white hairs coming out of the knods)