Just checked the plants today and it seems that the 2 topped plants will be females, and the 2 untopped plants will be males. Only sure about 1 male and 1 female till now, I'll know for sure on the other 2 plants till the weekend update. But I love it, cause the untopped plants already got to be too tall compared to the topped ones, so having the 2 plants that are more compact as females is great. Other than that, plants look happy. I'll stay with the 150W MH for now, if they get too stretchy I may have to change to 400W, but I think 150W is ok for now. Topped ones are under 35 cm height including the cups. And the bulb is in a cooltube so it stays very close to them.