A garden pond is essentially a giant aquarium. The most basic garden ponds reproduce a natural aquatic environment with a basin, pump, tubing and electrical equipment. More sophisticated garden ponds include additional pond equipment such as pond liners, real or faux rocks and gravel, filtration systems, skimmers, lights, foggers, etc. Regardless of how extravagant your garden pond is it will require proper aeration, bacteria levels, temperature and other factors important to the health of the fish and other wildlife that you choose to occupy your pond. Many online garden centers and specialty retailers are one-stop-shops when it comes to garden ponds, pond maintenance supplies, fish food, fish and wildlife, medication and remedies for all forms aquatic life. Simple fiberglass ponds are approximately $200 online, and can exceed well over several thousand dollars for a more elaborate garden pond with sculptures, fountains and lighting features.