How long until i can sex these?

Hey, i've been growing these guys for about 4 to 5 weeks i would guess, looking back i honestly have no idea. That was a pretty busy time and i just started them on the side not really knowing if i was going to go through with it. Reguardless, i have three inside a box with 96 watts worth of t-5 two footers. THey're in fox farm soil, the kind with earthworm castings and stuff like that, you dont have to use product on for 3 weeks. I was just wondering though when i can sex these to pull out any males?

Also any comments/tips about the grow... let me know.

You can sex them whenever you want. Just begin a 12/12 light schedule and within about two weeks they will show sex.

yeah but dont put them on a 12 12 light schedule now. yould end up lwith little baby plants a not very much yield. try tying a little black bag and zip tie it at the end close to the main stalk. and make one are of the plant go 12 with light , 12 without. then you can tell while you let them veg a little longer

i guess up until now, i thought you could sex them and then continue vegetative growth. I assume this isn't true though after what you just said? When exactly does pollination occur therefore when do i have to sex them by to stop it from happening?

If you want to sex them, but maintain the vegetative growth phase you should do it via cloning. What you do is take a single clone/cutting from each plant. Keep the clones under 24hr florescent lighting for two weeks, so that they establish roots. Then, change the light cycle to 12/12. After another two weeks, your clones will show their sex and you'll then know which plants are males and which are females. The whole time you are doing this with the clones, the original plants can remain on their normal vegetative light cycle continuing to grow. Once you sex the clones, get rid of the plants that correspond to the male clones.