Aquaponics is an agricultural system that combines both aquaculture, the practice of farming aquatic animals, and hydroponics, the practice of farming plants in nutrient-rich water. Aquaponic systems are used to farm a variety of plants and animals, and they are typically designed to be highly efficient in both production and resource conservation through the use of natural systems with minimal human or mechanical intervention.
Although aquaponic systems can vary greatly depending upon the desired outputs of the system and its sophistication, they typically contain some or all of the same functions and components that keep the system sustainable. Rearing tanks serve to house, raise and feed aquatic animals that are a part of the system. Settling basins catch uneaten food, animal waste and other large particles that must be removed from the system. Biofilters containing specialized bacteria break down ammonia and other animal by-products into nitrates. These nitrates provide the plants in the system with nutrients, and the cleansed water then flows back into the rearing area through a sump.
Modern aquaponic systems with components such as biofilters and pumps are relatively new to agriculture, but the idea of combining aquaculture and hydroponics is not recent. For instance, farmers in Indonesia, Thailand and China have cultivated both rice and various species of fish together in paddy fields long before hobby and commercial aquaponic systems came into existence.