I am considering moving my potted sarras to a mini contain bog. (I don't have that many...yet). It has to be small so its moveable. I'm looking at those little plastic things people use for ponds. I saw one tonite that was 7" inches deep. Then it jumps to one that is 15" deep which looks too deep to me (and would probably be heavy once filled with drainage material and soil). But 7" doesn't sound deep enough. Anyone have any suggestions? I don't want anything too ugly. And also, would it be alright to leave undrained (no drainage holes)?