Welcome to the Party.
Might be good to start flowering when the plants are almost 12-16 inches tall in such a small space.
If they double in height you won't have much room to play with. It's better to have smaller plants
that are not stressed out. Then to grow a jungle where the plants are all touching the roof and
they are too close to the lights. With each grow you can fine tune as you go.
BTW: Once you get 50 posts you'll be able to edit posts and send PM's.