Aquaponics system fish

An aquaponics system integrates fish farming and plant cultivation in a closed, sustainable cycle.

About this subject

Aquaponics is a production system that combines aquaculture (raising aquatic animals, such as fish) with hydroponics (growing plants in water). In this cycle, fish waste provides nutrients for the plants, which in turn filter and purify the water, which returns clean to the tanks. This method reduces water consumption by up to 90% compared to traditional agriculture, and eliminates the need for chemical fertilizers.

In Brazil, aquaponics has gained ground in urban and rural projects, especially with the use of tilapia, a hardy and fast-growing species. The most common plants are lettuce, basil, mint and tomatoes. The system can be scaled from small home gardens to large commercial units, offering a viable alternative for food security in water-scarce regions.

Historically, ancient civilizations such as the Aztecs already used chinampas, floating islands that combined fish and vegetation. Modern aquaponics, however, was developed from the 1970s onwards, with advances in pumping and biofiltration. Today, it is a global trend aligned with the UN Sustainable Development Goals, particularly in fighting hunger and environmental degradation.

One of the biggest challenges of the system is balancing the number of fish and plants, as excess ammonia can poison the animals, while too few nutrients limit plant growth. Therefore, sensors and automation are increasingly used to monitor pH, temperature and dissolved oxygen.

Frequently Asked Questions

How does an aquaponics system work?

Fish produce ammonia through excretion, which is converted into nitrites and nitrates by beneficial bacteria. Plants absorb these nitrates as nutrients, purifying the water that returns to the fish tank.

Which fish are most used in aquaponics in Brazil?

Tilapia is the most common species because it is hardy, fast-growing, and well adapted to tropical climates. Other fish used include carp and pacu.

Which plants can be grown in aquaponics?

Leafy greens like lettuce, arugula and spinach are ideal. Herbs (basil, mint) and fruits such as tomatoes, bell peppers and strawberries can also be grown, provided the system is properly sized.