- The principle of aquaponics
- The origin of aquaponics
- What plants and fish in aquaponics?
- How to get started in aquaponics?
We must not look for ancient etymological roots in aquaponics because it is a portmanteau word that summarizes well this mode of culture resulting from the fusion of words fish farming and hydroponics, the first being the breeding of fish and plants in the aquatic environment, the second relating to the cultivation of plants carried out on a substrate regularly irrigated with a nutrient solution. In short, aquaponics creates an ecosystem between growing plants and raising fish whose manure is used as fertilizer.
The principle of aquaponics
Aquaculture or fish farming, which consists of raising fish in ponds, poses an environmental problem because the water is regularly polluted by manure containing ammonia, which forces it to be changed regularly.
Aquaponics remedies this by filtering the ammonium from the water through a biofilter composed of Nitrosomonas bacteria that convert ammonium into nitrite. Subsequently, other Nitrobacter bacteria will convert nitrite to nitrate, which can then be absorbed by plants. The plants feed on nitrates and the filtered water is reused by the fish. It is important to monitor the pH of the water which should be between 6 and 7.
The two tanks - fish and plants - are thus connected and the water that must be between 18 and 30° C is recycled in closed circuit, which ultimately requires little water, while allowing interesting productions both at the level of fish, with a productivity equivalent to a fish farm, as for plants that can give more quickly and as much or more than a hydroponic crop.
The origin of aquaponics
Aquaponics comes from Asia with rice-fish farming in which fish farming was associated with rice cultivation: fish droppings fertilized the rice paddy while rice feet purified the water. Since the fourth century this technique is used in China, despite a brief stop during the Cultural Revolution.
In South America, the Aztecs have long practiced aquaponics with chinampas, until the sixteenth century.
Today, aquaponics is back on the scene, in isolated or very cold island regions, but also in the metropolis where it is part of the concepts of urban agriculture in vogue.
What plants and fish in aquaponics?
In aquaponics, plants are placed in bins filled with clay balls or pebbles. The plants most adapted to the aquaponic culture are leafy vegetables (salads, spinach, chard, leeks, watercress...) and aromatic plants (basil, chives, parsley, mint, coriander...), for starters. Then you can get started in tomatoes, cucumbers, squash, eggplant...
Specialists and more advanced gardeners will be able to grow all the vegetables, including carrots, turnips and potatoes, however the technique becomes complex.
Among the fish that you can raise in an aquaponics tank, freshwater fish have their place, common carp or koi carp, trout, perch, pikeperch, but also tilapia, black bass, crayfish, shrimp... Avoid buying industrial flours to feed them, and prefer the cultivation of lentils of water, rich in protein, whose growth is very fast, or use the supernumerary worms of your vermicomposter. It depends on whether it is herbivorous or carnivorous fish.
You will also be able to eat fish from your own farm.
How to get started in aquaponics?
If you want to start aquaponics, you can start by acquiring an aquaponics kit to understand and master the technique. Then, if you are seduced, you can develop and manufacture more elaborate and larger bins.
It may not be necessary to have a huge area to start with. Moreover, the tray can be installed indoors (garage, veranda, greenhouse...) and outdoors (garden, courtyard, roof...) depending on the climate of the region.