The concept of aquaponics, including a brief history of its development and its place within the larger category of soil-less culture and modern agriculture. It discusses the main theoretical concepts of aquaponics. It then moves on to cover important considerations of water quality parameters, water testing, and water sourcing for aquaponics, as well as methods and theories of unit design, including the three main methods of aquaponic systems: media beds, nutrient film technique, and deep water culture.
Traditional agriculture is having trouble, water supplies are running out and food demand is only increasing, and there is also a growing demand for crops grown without the use of chemical pesticides and fertilizers. Just because we’ve always done things one way, doesn’t mean that’s the best way. This is true of many things in life, and as technology advances many things change. Technological advancements have been very beneficial to the world in terms of food production. Recently though,there has been a radical new approach to growing produce, aquaponics. With aquaponics the need for soil is completely eliminated, and the need for chemical fertilizers is also eliminated.
Aquaponics is a method of growing plants, particularly vegetables, in a soilless medium where all the nutrients that the plants require to grow are provided via water that is circulated around the plants root systems. This process differs from hydroponics due to its use of fish to provide the essential nutrients instead of manufactured hydroponic fertilizers. The use of fish to grow plants in aquaponics also has the added benefit of providing fish to harvest as well as plants. Aquaponics is essentially the combination of aquaculture (farming fish), and hydroponics (growing plants in a water based medium).
The secret to aquaponics is bacteria. An aquaponic system is an almost entirely closed loop system where the only inputs to the system are fish food and sunlight. When the fish feed they produce waste which is primarily ammonia which is water soluble and begins to cycle through the aquaponics system. This ammonia is toxic to the fish and useless to the plants.
This is where bacteria come into play, naturally occurring nitrosomona bacteria use oxygen to convert ammonia into nitrite and then nitrobacteria convert the nitrite into the nitrate that the plants need in order to thrive. This nitrate is harmless to the fish and required by the plants and the key to the success of aquaponics. This nitrate is what functions as the plants source of nitrogen and thus what eliminates the need for fertilizers to be added.
There are several types of aquaponic systems, each has its own advantages and Disadvantages but media filled beds tend to be the most popular for home gardeners, Nutrient film technique and deep water culture tend to be used more in commercial Operations. These beds can either be set up to flood to a set level, drain, and then repeat, or as a constant flow which holds the water at a steady level and fills at the same rate it drains. The final option is deep water culture. This method uses large volumes of water pumped from fish aquariums into long troughs that are kept at a constant level and plant are suspended above the water.