If your'e still building the pond, you should try a wet-well. Depending on the amount of water needed, it is a pipe a few feet in from the shore straight down 6 to 8 feet with a smaller pipe into the water 90 degrees at least 4' down. The end needs mesh or something to keep the fish out. The intake hangs into the vertical pipe in cleaner water. We have used 16" to 48" for different size pumps. There is a formula if you google wet well.