We recommend a combination of different types of fish to keep your pond in balance. If only one type of fish is stocked, like only bluegill, the fish will overpopulate the pond and be very small. By stocking bluegill with largemouth bass, black crappie, and channel catfish, the predatory fish like the largemouth bass and black crappie will keep the bluegill population in check and you will have fewer larger bluegill and very nice size largemouth bass.