Link at the bottom if you do not know what I am talking about. Fish tank that works like pet watering bowl. If you poked a hole at the top air would go rush in. If you poked a hole at the bottom water would rush out. At what point in the tank would water be under so little pressure, the tension would be enough for it to keep from leaking? http://www.okeanosgroup.com/blog/aquariums/fun-with-physics-bottomless-fish-tanks/ [Broken] This is a brain teaser but I don't have the answer yet.