Interviewed & Written by Kira Ginter
Aquaponics combine hydroponics, the growing of plants without soil, and aquaculture, the growing of fish in a closed environment. The goal of aquaponics is to produce a more sustainable and maintainable food source for people. The fish in the system eat food and excrete waste which is then converted to nutrients for the plants through bacteria. The plants in turn, purify the water as they absorb the nutrients. This cycle produces food through the fish and whatever plants are grown in the system, whether it be leafy greens, salads, etc.
Carel van Heerden is a mechanical engineer who is working to promote sustainability by providing mechanisms that work towards zero-waste food production and zero-hunger. Carel and his partners at Green Stream nutrients are “creating a sustainable nutrient production system with a positive footprint by harmonizing renewable technologies to produce high-value food streams accessible to all.” They are utilizing aquaponics to provide a more sustainable, greener food source via the fish and plants grown.
At Clanwilliam in South Africa’s Western Cape province, Green Stream nutrients has a 10×40 meter pilot plant facility as a reference for clients. Commercially, aquaponics facilities can operate in large spaces, but it can also be done in a more scaled down format. Idealistically, it will be done in a something as small as a fish tank so that a homeowner could produce their own leafy greens, salads, and fish. Aquaponics is suitable for everyone—the operator does not necessarily need to understand the processes in-depth to maintain their own facility. Carel likened an aquaponics setup to a car; anyone can learn to drive a car and they do not have to understand the mechanics of the vehicle in order to do so.
Aquaponics supports the concept of a circular economy because it is a solution that allows neighborhoods to be at the center; for example, communities can have one centralized aquaponics site or individuals can maintain their own fish tank sized sites. It is an incredibly effective growing method promoting greener lifestyles because it allows plants to grow throughout the year due to it being climate controlled instead of only operating during peak growing seasons.
Carel states that “This system uses biological systems in which you reconstitute or recycle the waste that you produce into a form where you can consume it again, using biological systems and managing them to their optimal levels so that you can really get to something that turns a waste stream into something that is valuable at the end of the day. It is an ecosystem that creates and manages itself.” Due to managing itself in a way, this ecosystem is able to function consistently year-round in desirable conditions. Being able to function year-round provides communities with more consistent access to food; thus, ensuring that people do not have to go hungry.
Aquaponics is not susceptible to soil-borne diseases, since there is no soil involved in the growing process. It also is significantly more water-efficient than traditional agriculture because of its circular approach that produces very little waste. Aquaponics uses neither pesticides nor herbicides, so the food is chemical free in that aspect.
Adopting aquaponics allows for communities to have more consistent access to sustainable food, fewer soil-related growing issues, and safer food overall.
van Heerden, Carel. Personal interview. 28 Oct. 2022.
“What Is The Aquaponics System? Definition, Benefits, Weaknesses.” you matter world, 16 May 2020, youmatter.world/en/definition/aquaponics-sustainable-benefits-system/.