My room is a mere (9' x 12') - 108 Sq. Ft. ...Somehow, I managed to get a 140g, a 55g, and a 10g in here...along with my PC desk, & bed. (I also have 2 full grown Sib. Huskies, in this rm.) My 140g is over 6' tall(with the canopy on), & I only have a 7' ceiling, 10" clearance to ceiling, but I make it work. Oddly, I have it in the back of my mind, that I think I need a few more, I'm just not real sure where to put them. Going to sleep & waking up to a wall of water, is...awesome!