i did basicly the same thing. started four to up my odds of a female, it came out 50/50 when the males showed i had 2 females that fit ok under that light(same as yours) LST the first ones if you need too for height. with a 150 i would probably grow 4 clones to 6-9 inches in 1 gallon pots for a sog effect. you have more room but not enough light for a 3x3 area.