The above-ground pond is perfect for growing fish. Most commonly goldfish, koi, yellow perch, freshwater sunfish such as bluegill, catfish and bass. Tilapia is the most common edible fish, and is often used in aquaponic greenhouses. Tilapia has more demanding requirements in terms of temperature and dissolved oxygen content than goldfish. Aquatic plants will also help control oxygenation and add nutrients for the fish.