As I understand the experience of Monterrey Bay Aquarium and Seattle, the jellies require a tank in which, beyond a certain size, they never touch the walls.
I have been in the propagation area of the Seattle Aquarium, and they do use small tanks for bringing the little floaters up to size, and they're turbulent without being violent. But as they get bigger, they have to go into the perpetual motion tank, which is a toroid you can walk through. These are moon jellies, genus aurelia, I believe, which, outside of the upside down jelly offered by Foster/Smith, seems to be the only species successfully cultivated for public display.