Wealth manager, Jack Probart, started Eden Aquaponics in 2013 on Shanzeley Farm between George and Uniondale in the Langkloof to prove to himself and others that aquaponics is a sustainable way to increase food production.
The technique is renowned for using fewer resources, such as land, water and fertiliser, than open-field production systems.
The first two years at Eden Aquaponics were devoted to getting the system right. During the past two years, the focus has been on fine-tuning.
“My father did a lot of research before starting the project and found little information tailored to the unique production conditions of South Africa,” explains Ruann Coleman, marketing and logistics manager at Eden Aquaponics. “With the system and production management under control, we’ve actually started making money from commercial sales.”
The company’s ultimate vision is to empower others to produce their own food. “The idea is to provide support services to individuals or companies who want to use aquaponics to grow their own food and become self-sustaining.”
How it works
In aquaponics, waste water from an aquaculture system is fed to a hydroponic system. Bacteria break down the by-products into nitrites and then nitrates, which are used by the plants as nutrients.
The water is then recirculated to the aquaculture system, and the cycle starts again.
Ruann estimates that a properly managed aquaponics system could end up using less than 2% of the water required to grow the same quantity of produce in an open land.
Eden Aquaponics currently produces watercress, cabbage, spinach, celery, chives, coriander, parsley and a variety of lettuce in 16 000ℓ of water.
Tilapia are also sold on a limited scale, and are not intended as a second income stream.
Aquaponics: ‘economy of scale is the key’
Eden Aquaponics continually experiments to improve production. Here vermiculite is being trialled as a growth medium.
Although there is sufficient space to significantly increase its fish production, Eden Aquaponics keeps only as many fish as are required to generate fertiliser for the plants – between 3 000 and 4 000 fish at a time. “There’s not a great demand for fish in our region because we’re so close to the ocean,” explains Ruann.
He adds that the company can produce up to nine harvests of salad greens and herbs throughout the year, a yield that would be impossible with open field production due to climatic conditions.
“Plants under protection are also less vulnerable to pests than those grown outside. You can produce up to eight times more food with aquaponics than with open- field production systems.”