It all depends how many plants you want to fit in there and how big you want them. I use round pots so i'm not sure. I would suggest buying Budsforless book. It's pretty neat. He grew llike 4 or 5 ounces on one plant under cfl's and a really cheap set-up. If I remember right, it wasnt that tall either. You can have good yields with cfl's though and in small spaces. If you want to make a mother plant I would suggest SOG and just put about 5-10 clones in every week or two, and you have yourself a perpetual harvest. If you flower 2 inch clones then they will end up about 14 inches tall and yield between 10 and 28 grams. Not bad for one tiny plant not taking up much room. Dr.Budgreengenes on Icmag.com is the king of that. Check it out if you wanted some ideas on that.