Time to consult the pond gods.. I'm currently working on a job proposal for client with a different type of request. They want a swim pond a very large swim pond. The area is roughly 100' x 100' x 10' deep. The area at which there house is has heavily rock formations in the ground so digging a natural clay bottom pond is out of the question. I have two options to create one; one being a swim pond with a designed area for swimming or a a more traditional farm pond style with soil being shot over the the liner when installed. In the swim pond the designed area would be roughly 80'x80' and the remainder of the 100x100' area would be for the bog/wetland filtration using up-flow through the gravel areas. The actual swim area will have 3 - 4" inch bottom diffuser drains installed. Question is that enough filtration for this pond? or designate a larger area for filtering? Any pump suggestions I'm leaning toward 20000 gph maybe a little more. I know slower is better when working with wetland filtration. I also know that trying to filter this big puppy completely in a timely matter is out of the question.. I know water clarity will not be clear all the time and the use of U.Vs would be over kill and expensive because of the number of watts needed for this project. So mother natural will have to get her butt in gear lol.. The other option is a farm pond with liner. Again i would use up filtration thru bogs around the perimeter as well as bottom aerators no bottom drains. However this style would be set up as a pond for stocked fish and swimming as well so the aeration is more key than filtration.