whats your lighting? i dont do SOG because of the number of plants needed but ive been told that 1gal pots, 24 under a 1000hps w/ a 3-5 day veg works great.
3x7 is tight, i had a veg room that size that i used a 600hps w/ a mover and it worked great. i did finish one run in there w/ the mover but it produced less bud than other non moving lights.