Aquaponics combines aquaculture with hydroponics for a symbiotic system. Aquaculture, or aquafarming, refers to raising fish, mollusks, and even algae in a controlled environment. Combined with a hydroponic system where nutrients released by the fish soak up the roots of the plants, thereby feeding the plants.
In aquaponics, you are creating a natural ecosystem where you rely on the organic process of converting solid waste from the fish into complete plant food. It is a delicate system where if you apply pesticides to the plants, then the fish will suffer or if the fish consume hormones or anitbiotics, the plants suffer. Aquaponics lends the control of an entire ecosystem, where what you put in is what you will get out and everything interacts with one other.
The science behind the evolution of a modern aquaponics system can be attributed to the work of the biologists at the New Alchemy Institute. From the 1970s, the new Alchemy Institute lead research in enviormentally controlled gardens along with Dr. Mark McMurtry from the North Carolina State University. Today, the Aquaponics Association at NC State has lead the way in creating guidelines for safety audits on large-scale aquaponic farms.
Typical fisheries that run aquafarms must replace 10%-20% of the water in their tanks daily to prevent ammonia build up. This results in tremendous water usage. In an aquaponics system, the plants use the ammonia, so replacement of the water is not necessary.
Water in other hydroponic systems should recycle as mineral build up becomes toxic to the plants. This is both inconvenient and problematic especially considering the disposal location of this wastewater is important. Rather than having these problems with disposal or chemical imbalances, aquaponics systems create a symbiotic balance that is the hallmark for a healthy ecosystem.
There is a wide range of fish that are suitable for an aquaponics system. The best way to choose is to decide whether your fish will be ornamental or if you want fish to eat. Tilapia are the most popular if the goal is to raise fish to eat because it is a warm water fish species that can tolerate crowding and changing water conditions.
Koi and goldfish are great for an ornamental aquaponic fish. They supply beautiful color to any system as well as make great pets. They can withstand a wide range of pH level and temperatures. Though, be aware that a well-fed fish can become a massive fish so be sure that the tank used is large enough to accommodate.
There are “junk” fish feeds that most fish cannot digest properly. This is a big problem for the decomposition of fish waste. If it does not decompose, it is possible to find a film of the waste on your roots. Organic fish feeds may prove to relieve that issue as they will decompose fully in the water. You can also grow plants for the fish to eat such duckweed, or worms from compost, as well as using prepared kitchen scraps.
An aquaponic system is also quite scalable. Systems can vary in size from a small countertop model to a full-on large-scale farm. Aquaponics and hydroponics vary widely in labor, materials, and production. With a large aquaponics system, it may be best to go for profitability to fund the system.
Any plant that is common in salads has the greatest success in aquaponics. That includes cucumbers, shallots, onions, and snow peas.