The smaller hookahs or shisha pipes: 13 inch tall (or rather: 13 inch short). Although size doesn't really matter with hookahs, 13 inch is what I consider somewhat below the comfortable minimum. But, of course, that's my personal opinion, based on my experience that much of the "soot" gets filtered out not in the water but in the standing tube - which in a 13 inch hookah is really a bit on the shortish side. Most of my own pipes are somewhere around the 30 inch range.