We had a 50x30' irrigation pond out at our old place. It was about 5 1/2 feet deep in the middle. We stocked it with native minnows, goldfish, bluegills, and bass, and had a bunch of hornwort, lilies, smartweed, and other water plants that found their way in. No feeding, no filtration except a small waterfall, but fairly huge water changes once a week or so as we pulled water out to irrigate and replaced it with water from the ditch. The goldfish got HUGE, vibrantly colored, spawned like crazy. So did the bluegill and bass eventually. Raccoons, deer, great blue herons, leopard frogs, and assorted snakes were frequent visitors. But the fish were victims of of their own success. It got so overpopulated that all the fish winter-killed under the ice.
Mrs. Badger and I always wanted to make a pond up against the house, and replace one of the walls of the house with plexiglass so we could look right into the pond. It would require some serious engineering...but it sure would be fun.
