just get whatever gives you 3000 lumens per square foot minimum and if u want better results buy more lights.. EXAMPLE__ you have a 3 foot by 3 foot grow area then you need at least 27,000 lumens.. if you have a 2 foot by 2 foot then u need at least 12,000 lumens..
nah man he right you kant do it back to back it will shock ur plant and it will be like 80-90 percent chance it will be male, and even if it doesnt go male ur plant will halt growth for up to a week.. just go with topping them and giving it a week.