Male or Female.. when to switch to 12/12?

First time starting straight from seed.... First off what you think these two babies are? They are on day 15....

Secondly... I am trying to keep them right at 3 ft high. It is day 15 now. How long/ High should I let them grow till i switch to 12/12 to induce budding and not let them get bigger then 3 ft? I have other plants going but I only included the one picture to just give you a hieght visual.


Thanks.

First two pictures are of the same plant just diffreent angles

Keep this in mind they will at least double maybe triple in size when you put them into flower. So a guess would be a foot.

switch them to 12/12 now an find out if they r male or female theres no point waisting time an money an they end up males

goodluck

so yall think Ill be alright if I switch them to 12/12 in like 5 days i guess? I at least want the others to catch up somewhat (they were started about 2 days later)

They're way too small to be flowering in 5 days, you should wait another 3 weeks and they will still be short.

pre flower them, should take 7-10 days untill there sex forms, find an kill the males and then set the girls back into veggin