Hydroponics and aquaponics have some similarities. They both use nutrient-rich, highly oxygenated water to bathe plant roots continuously. Indeed, in both systems, the plants experience better development rates than those grown in the soil. Hydroponicsuses only water and chemical nutrients to grow plants. Moreover, this technique does not require soil. In addition, it is the main production process for a large portion of greenhouse-grown vegetables in North America. These vegetables include tomatoes, basil and lettuce. Using hydroponics to grow plants has the following advantages:

No soil is required
It is stable and produces high efficiency
Pesticides do not cause harm
The controlled system means that no nutritional pollution is released into the environment
A reduction in nutrient requirements due to the control of nutrient levels
Reduced water requirements since the water stays in the system and can be reused.

There are many important differences on which aquaponics and hydroponics are different. Indeed, aquaponics is more efficient. However, aquaponics uses many of the same techniques as hydroponics, such as NFT (nutrient film technique) and DWC (deep water culture). More and more institutes and gardeners around the world, at all levels of society, adopt the aquaponics method. So it is only a matter of time before this sustainable food production system becomes widespread.

Aquaponics : definition

An aquaponics system is a food production process. It combines traditional aquaculture and hydroponics. Animals and plants in an aquaponics system have a symbiotic relationship. Indeed, aquatic animal effluents are used as food by plants. By doing so, the plants purify the water for the aquatic animals. In addition, aquaculture and hydroponic techniques form the basis of aquaponic systems. They concern the complexity, size and types of food/plants grown in aquaponic systems.

Aquaponics diagram

Aquaponics Cycle

Fish breeding tanks: in the water, the fish are fed. They produce droppings rich in ammonia.
Mechanical filtration: the water of the breeding ponds contains particulate and dissolved waste. A drum filter removes this waste.
Buffer tank: the water flows to a first intermediate storage tank, the buffer tank.
UV disinfection: an ultraviolet treatment allows the destruction of bacteria and viruses contained in the water coming from the breeding ponds.
Biological filtration: a biological filter serves as a support for specific bacteria. They convert ammonia into non-toxic nitrate.
Degassing: the nitrogen gases are then removed by degassing. The cleaned water is now loaded with nutrients. It is recirculated for return to the fish tank.
Buffer tank plant line: a second buffer tank connects to the first one. A valve allows their operation to be dissociated.
Soil-free cultivation system: the water in this second basin flows into the soil-free cultivation system. The plants assimilate the nitrate, necessary for their growth. They purify the water before it is returned to the plant buffer tank.

This operation allows the plants to benefit from nutrients from the waste produced by the fish. Thus, almost all the water in the circuit is recycled.

What is the general operating principle?

Aquaponics is somewhat similar to market gardening. Usually the seeds are planted and watered. We sometimes add fertilizer and weed the garden. Invasive insects are removed, then the wait begins to see if the plant will grow or not.

The difference between aquaponics and traditional gardening? Aquaponics takes care of most of these processes automatically.

Aquaponic systems work by creating a nitrogen cycle.

In this system, an aquarium and culture beds share the water.
The fish will then produce waste products with high ammonia content in the aquarium.
The pumps then transport this waste to the cultivation beds.
In these beds, the bacteria will transform them into a fertilizer extremely rich in nitrogen.
The vegetables then extract nitrogen from the water. This makes it safe for reintroduction into the aquarium.
And this cycle will repeat itself again and again.
The fish provide the basic nutrition for the bacteria, the bacteria provide the nutrition for the plants.
And finally, the plants act as a bio-filter for the fish.
All that remains is to feed the fish and decide which plants to grow.

Benefits of aquaponics

Cost of chemical nutrients

In a hydroponic system, the chemical nutrients used to feed the plants are expensive. Costs are gradually increasing due to overexploitation and scarcity. In an aquaponics system, the fish feed is used instead. This is not only less expensive, but it will also provide a larger and more effective support for the plants.

Retention nutrient solution

During certain periods, the accumulation of salts and chemicals in the water in hydroponic systems require the cleaning of the water. Some amounts are toxic to plants. Also, the location of the wastewater discharge must be carefully considered. In contrast, in an aquaponics system, there is a natural nitrogen balance and water is never replaced. Evaporation completes the balance.

Productivity

Several studies and research show that the aquaponic biofilter is completely established after a period of 6 months. After that, an aquaponic gardener usually gets faster and more effective results. Plant growth is better withaquaponics than with hydroponics.

Easy to maintain

An aquaponics system is much easier to maintain. Indeed, it is not necessary to check the electrical conductivity once a day. The natural ecosystem of aquaponics means that the elements tend to balance each other. Therefore, it is not necessary to check pH and ammonia levels more than once a week.

Also, nitrate levels are checked only once a month.

Organic growth

One of thedifferences between aquaponics and hydroponics is the environment.

In fact, hydroponics has a sterile artificial environment.
In reverse, aquaponics is a replication of a natural ecosystem.

The system is thus completely organic. Hydroponic systems use expensive nutrients consisting of a mixture of chemicals and salts to feed the plants. In an aquaponics system, the conversion of solid fish waste by bacteria and composting worms produces plant food. This natural process results in better plant growth and lower disease rates. (Home aquaponics system, 2019)