clone sooner or later?

I was given an ebb and flow hydro system from my friend, no clones available. I started several seeds in a couple of clay pots, growing in soil and have now moved them into my veg box under floro lights (using 600W Super HPS EN later). My plan was to grow them just tall enough to clone, cut the whole thing and put them into rockwool to start the hydro setup. After much reading I'm wondering if I should let them mature 6-8 weeks, check for sex, pull the males, then clone? They have been going for 2-3 weeks and look good, but I'm not sure how long I can grow them in the pots, I have about 15-20 per pot. In hindsite I know I should have used many more pots. Should I let just them mature, thin them out and mature or cut them soon and re-root them in rockwool? I dont really want to waste the hydro system to grow males but I also don't want to pull too many and then get lots of males and not have very many plants. Need advise. Thx

Personally I'd bring your light cycle down to 12/12 to force the plants to show sex. Once you find 4-6 good females out of the bunch pull the rest to give room for the good healthy females. Put it back into 24/0 to bring them back into veg. Grow them for another month and then take all your cuttings. You can also just keep these 4-6 females around as mothers to pull as many clones as you want by keeping them in 24/0.

if u have the time i would also advise u to sex them first. u could clone them now, and make sure u label what clone comes from what plant, then put all ur soil in flower and just keep the clones that came from female plants, at least u can have a head start on getting some buds if u do it this way. Might as well get past the screwing up ur probably going to do if this is your first grow

Thxs, I'll forced them and clone.