I use my basement closet which is approx 3 ft wide by 5.5 feet long. I can only fit three, sometimes 4 adult autos in there at a time. They'll get big if you use big pots and treat 'em right. I've never pulled less than 1 oz off one plant. I average about 1.3 oz per plant. Keep in mind I'm using a 400w hps air cooled, with about another 400w CFLs so its pretty frickin bright in there. Short Stuff Seeds are good I've grown Auto Assassin, Snow Ryder, MI5, and Blue Diesel all of which I would recommend to anyone.