you could make it through veg with no nutes if you were using miracle grow soil that has the time release food in it. To make it through flowering and be worth anything you will need to feed them. Walmart has all purpose plant food for 4 bucks.
I don't think that is anything to be overly concerned about. Just let it dry out real good before the next watering. I would have to lean toward possible over watering. Still looks fine.
what are the temps? what do the roots look like? what is your ph doing? I could go on and on with all the info you left out for someone to try and help you.
your pics are not showing up . I am not sure how small they are they may have hit the bottom and sides already and it might be time to go larger. Plants grow to the size of their pots. If it is stunted I would think you might need to transplant.
if you are limited the 3 feet tall, i would go with a 600 over a 1k.
I read that wrong. Sorry. To answer your question if you are growing monsters maybe 4 to 6 plants.
I have a question about rep also, If a person doesn't have any points to give you, it shows up as gray, and you do not get any points. So when they do have enough points for rep, do you get those points?