I need some flowering help

I was just wondering when I should start flowering my plants to show the sex?
They are about 4 weeks old right now.

honestly i would say to go ahead and start flowering them i flower some of my seedling as soon as 4 weeks after i crack the seed looks like you topped that one to make horns lol ....yea go ahead and induce flowering

depends on how much room you have to play with and how much light you have. personally, i would wait until they get at least 3 or 4 more sets of leaves. to begin flowering. usually plants are about a foot tall when they have enough growth to flower.

i would veg like 10 more days atleast

That's the thing i'm currently using a single 45w flourecent, but i have a 400w MH.
Unfortunately i haven't the room for it right now. The following pics are what i'm curently growing in.
It's not an ideal space to say the least, but I have a room I'm working on that is about 4'x4'.
This is my first time growing, so I'm basically going on trial and error