What is surprising in wanting to pick beautiful and good seasonal fruits in your vegetable garden? The taste is incomparable to that which can be found on supermarket shelves. But in the face of sometimes disastrous bad weather, upset weather conditions, the spread of uncontrollable parasites, it becomes difficult to ensure a personal harvest. So it is tempting to treat your vegetable garden, with processes that sometimes destroy microorganisms and biodiversity. This is why we would like to present to you a rather original mode of culture, which is none other than aquaponics. Make way for presentations (and why not, adoption!).
Aquaponics: What is it?
To put it simply, aquaponics makes it possible to grow organic, fresh and seasonal fruits and vegetables, without any use of fertilizers or pesticides. Miracle will you tell us? No, but ingenious, environmentally friendly and 100% organic, yes, definitely! We explain to you.
Aquaponics results from the combination of aquaculture and hydroponics. Aquaculture is a farming method fish or other organisms in an aquatic environment (algae, crustaceans, molluscs). It is practiced in rivers, in ponds, or even by the sea. In this case, we speak more of marine culture. If it has many advantages, too intensive a practice of this mode of culture can lead to the degradation of marine and coastal ecosystems, because it is not uncommon for it to involve the use of chemicals, and the concentration of a activity can denature the aquatic bottom and disturb the existing fauna and flora.
For its part, hydroponics is a method of growing above ground. plants with water enriched with minerals. The cultivation of the plants is then carried out on a neutral and inert substrate, such as sand, clay balls or other. An irrigation system brings water and food to each plant in place in the greenhouse. It is also a winning formula, totally protected from the vagaries of the weather, without water evaporation, therefore allowing significant savings, and the possibility of cultivating all year round.
Aquaponics is therefore a cultivation technique that consists of recreating a miniature ecosystem in which fish droppings serve as natural fertilizer. The water is then loaded with nutrients and transported to the growing tank where the plants feed on them, and in turn purify the water. This is a very interesting earnings/action cycle. The water circulates there in a closed environment and is thus self-recycled.
This cultivation technique is ancestral, used for millennia in Asia and Latin America. We Europeans, whose ecological consciences are gradually being awakened by a climate emergency that is driving us crazy, have only developed this practice very recently, some twenty years behind Japan or Canada who saw it also an incredible interest.
The benefits of aquaponics
Aquaponics offers a long list of advantages, but here are the main ones, absolutely undeniable:
- Many bios : In addition to the pleasure of healthy cultivation while respecting the environment and respecting the product, you respect your body by enjoying good seasonal products that are totally natural and organic;
- Economiser : A few figures will suffice to convince you of the savings achieved: 0% is the rate of fertilizers and pesticides required in aquaponics; 95% is the water saving achieved compared to growing in the ground; €1 is the electricity budget needed per month to grow its products; several tens of euros is the budget saved in supermarkets on fruit and vegetables;
- save space : The roots, having all the nutrients they need, do not spread out like in a vegetable patch. Thus, they do not compete with each other, therefore do not choke each other. This makes it possible to grow vegetables and fruits in close proximity, with the guarantee that everyone finds their place there;
- Grow more efficiently : By avoiding both water loss due to evaporation by the sun, and to burial in the ground, and by allowing fruits and vegetables to benefit from a daily supply of natural fertilizer, they grow 2 to 3 times faster than in a conventional vegetable garden, for unparalleled nutritional quality;
- Act with eco-citizenship : Respect for the planet is everyone’s business. Every action is important, if only for his own self-esteem to act for his health. One action for the environment and biodiversity often leads to another. It is an inexhaustible source of self-satisfaction which becomes an addiction;
- Make the culture pedagogical : The fun aspect of aquaponics can be shared with family, children, spouse, neighbors or friends. In short, organic farming leads to organic farming, the organic lifestyle, and the spread of good ideas and everyday tips. It’s a good moment of sharing to observe the evolution of the ecosystem.
How to set it up?
The method most frequently installed on a small scale in private homes is that of the bed of inert substrates. This system therefore requires a tray containing this substrate, which will generally be expanded clay balls or gravel. A fish tank supplies the plants with water, either continuously or discontinuously by a system reproducing the phenomenon of the tides, with flooding then drainage, and this in a repetitive manner.
Ideally, it is best to install the system in mid-spring. Thanks to the milder temperatures, without being very hot, bacteria will be able to proliferate to form the ecosystem. The fish tank and the culture tank should not be too big to start. This will allow you to familiarize yourself with the process, and to form your opinion. Finally, a pump will be needed to draw water from the fish pond to the culture tank.
Plan ahead! Before buying fish and vegetable or fruit plans, make sure your system is working properly. Test the suction system of the pump, and make sure that no leaks are detected.
A process to follow for the comfort of fish and plants
You will need a kit for measuring the different water parameters, like the one used for an aquarium. The tests will make it possible to evaluate the content of ammonia, nitrites, nitrates, and the pH of the water. They will ensure the well-being of the fish.
You can then bring ammonia into the system to feed the bacteria, either pure commercially available, also known as pure ammonium hydroxide, or added to the fish food. The correct reading of the ammonia level indicates 2 ppm, or 2 mg per liter of water. After a few days, nitrites will appear. They will be the result of the work of nitrifying bacteria. Ideally, the nitrite rate will be around 0.5 ppm.
As soon as the nitrates appeared in turn, the nitrites should show a rate of 0 ppm. This is the perfect time to insert the vegetable seedlings into the grow tray. Fish can also be inserted. Do not count more than 20 goldfish per 100 liters of water.
What choice of fish and plants?
Ideally, it will be better to prefer goldfish which are rather resistant. As for plants, prefer vegetables that are easy to grow, such as leafy vegetables (salad, spinach, chard), herbs (basil, parsley, coriander, mint, chives), and other plants once aquaponics has stopped. has more secrets for you (tomatoes, cucumbers, strawberries, etc.).