Aquaponics is an artificial ecosystem in which three types of living organisms are key: aquatic animals (usually fish), plants, and bacteria. This technology is environmentally friendly. It works according to the principle of fish and plant ecosystems: fish provide food for plants and plants purify water. The essence of the method is to use waste products of aquatic animals (fish, shrimp) as a breeding ground for plants. Aquatic animals excrete toxic products for themselves: nitrogen, potassium, phosphorus compounds, carbon dioxide. The accumulation of these substances in the water is the main problem in industrial aquaculture, as well as in a simple aquarium. These same substances are absolutely necessary in hydroponics, and they are added to the water to produce nutrient solutions for plants. In aquaponics this problem is solved by itself: fish waste products are utilized by bacteria and plants.
The essence of the aquaponics method
It is the use of waste products from aquatic animals as food for plants. Aquatic animals release nitrogen, potassium, phosphorus compounds, carbon dioxide, which in high concentrations become toxic to themselves. Bacteria, on the other hand, are able to break them down into constituents that can be assimilated by plants.
This process eliminates the need to use chemical fertilizers, with a complex system for dosing them. The entire process of chemistry, processing, and cleaning occurs naturally and in a closed-loop. In this way, aquaponics mimics the natural cycle of nature.
The most common aquatic animals used in aquaponics are freshwater fish – tilapia, silver perch, catfish. If the fish need not necessarily be edible, koi carp, roosterfish and goldfish are excellent. Freshwater crayfish and shrimp are sometimes used.
With regard to bacteria, it should be aerobic nitrobacteria – Nitrosomonas bacteria turn ammonia into nitrites, and Nitrobacter bacteria turn nitrites into nitrates. Care of the bacterial colonies is important to regulate the full assimilation of ammonia and nitrite. That’s why most aquaponic systems contain a section with a biofilter that helps facilitate the growth of these microorganisms.
Basic elements of aquaponics
An aquaponics system includes at least the following components:
- Fish keeping tank
- Container for plants
- Water pump for water
- Air pump for aeration of the water
As a rule, the fish tank is placed below the plant tank. With the help of a water pump water from the first tank with fish through a pressure pipe to the second. It is desirable that the water supply and the hole for the backflow into the aquarium to the fish are at opposite ends of the plant tray. This will ensure that the water flows through the entire tray, which means the plants can assimilate the incoming nutrients more efficiently.
The bio-filter creates optimal growth conditions for nitrifying bacteria colonies, and the air pump (aerator) saturates the water with oxygen, which is essential for plant root development and fish respiration.
Aquaponics can have a wide variety of designs. From the simplest, where the tank for the plants serves as a kind of lid of the aquarium with fish, to industrial versions, which include a whole pond with fish, several hydroponic modules for plants, settling tanks to collect excessive feed, and so on. Very common systems of plastic euro cubes