Aquaponics is becoming a popular hobby to produce fresh, natural food in the home. Aquaponic systems can occupy small spaces indoors or out and utilize less water than backyard gardening. It is active and very different from traditional gardening, which may be appealing to people not interested in conventional gardening.
What is Aquaponics?
Aquaponics is a method of growing fish and plants in a closed water system. Fish waste provides the plants’ nutrients, while the plants purify the water to help keep the fish healthy. An aquaponics system has separate fish and plant components that contribute to the overall benefit of this productive system. (Figure 1)
Ample space for the fish component is imperative for success. The fish tank must be large enough for a water circulation pump, proper aeration to maintain high oxygen levels, filtration to purify the water, and space for healthy fish growth. Water in an aquaponics system filters through two types of filtration. The first filter mechanically screens out fish food, feces, and other particles suspended in the water. The second is a biological filter that introduces beneficial bacteria that converts ammonia, toxic to fish and plants, to nitrate, an essential nutrient for plant growth.
The plant component helps purify the water, keeping the fish healthy while providing an opportunity to produce nutritious vegetables for the home residents. Plant production systems include deep well/floating raft, media bed, ebb & flow, or Dutch bucket/bucket systems. Each of these systems is practical but requires different management plans. No plant system is perfect, so one may choose a single design or incorporate many based on experience and space. Careful aquaponics system design is essential for optimum performance.
Base fish selection on whether the fish will be consumed or not. Some fish are good candidates for eating and provide an excellent dietary protein source, while some are kept for enjoyment. Foodfish (fish consumed for food) include warm water species like tilapia (Figure 2), catfish, bream, and hybrid striped bass. Goldfish and koi are excellent options for fish to be kept for enjoyment (Figure 3) because they provide an attractive fish display. Additionally, choose fish that can live in high densities and easily consume commercial fish food. Happy and healthy fish are vital because they are the nutrient source for the aquaponics system.
What Plants Grow Best in an Aquaponics System?
A balanced aquaponics system can successfully grow many vegetables. Leafy greens and lettuces (Figure 4) are common plants that grow successfully in an aquaponics system. Other vegetable selections, including fruiting plants like tomatoes, can be grown successfully. However, these crops require greater fish densities to produce high nutrient concentrations for successful production. Experience with the aquaponics system process is essential when attempting to grow a variety of more complex vegetables. While plant selection is relatively unlimited, some plants will not work. For example, most tubers or in-ground cultivated vegetables in a conventional soil system will not be successful in an aquaponics system.