For my pool I am using a drain. This is my setup,We haven't totally decided yet. But need to come to something more permanent because I had to bail and dump water this morning....it was nasty after five days. We have to pay for our water and it is imperative that I come up with something that won't break the bank.I am afraid I didn't think on that enough before getting ducks. Hubby is thinking of digging them about a 5' diameter pond in the big part of the pen....our water table is very high and close to the surface. We have had an horrible time trying to get it all finished with thunderstorms, HEAT, and totally undependable help. We have more to do but they HAD to get outside and so I am open to any suggestions.