Aquaponics is the combination of Aquaculture (fish farming) and Hydroponics (farming without soil) and entails the the design and commissioning of greenhouse-based systems growing fish (usually Tilapia) and vegetable crops in a  closed-loop system.

The major expense involved in building a Fish Farm is in the filtration of the water.  In Hydroponics, it is in providing sufficient nutrients for your vegetable crop.  In Aquaponics, nutrient-rich water is pumped (or flows by gravity) from the fish ponds to vegetable growbeds where the water is filtered and oxygenated by the plants.  Combining these two technologies thus offsets the negatives of each other.

Once cycled, a system like this can produce tons of fish and vegetables on a tiny footprint and using minimal water and power.  Although the capital cost is reasonably high, the yields from a well-designed system can provide a steady return within a very short period of time.

So where does Aquaponics fit into South Africa’s agricultural landscape?  Being independent of soil (the plants are actually grown above ground, in 13mm gravel) the condition of the soil is irrelevant.  This would open up vast tracts of otherwise unusable or infertile land for food production in this country.

One 30m x 10m greenhouse housing an Aquaponic system can yield the same vegetable crop as 1HA of soil.  Over and above this about 5-8 tons pa of high quality protein (the fish) is also produced.

Properly planned, the system has the potential to also support an algae pond capable of producing about 200L of clean, eco-friendly bio-diesel per week, enough for a small emerging farmer to run all of his vehicles and implements as well as a backup generator for the system itself.

To reverse the irreparable damage being done to South Africa’s food security by ill-planned land distribution to unqualified and under-capitalized emerging farmers, our Government should rather invest heavily in training and supporting the establishment of large, medium and small-scale Aquaponic ventures on land not currently used, or suitable, for large-scale food production using conventional means.

Aquaponic system could be built right where they are most needed, in small communities in the rural areas, providing food, employment and skills transfer.

Knysna Aquaculture, together with our Australian technical partners, are hard at work designing, building and commissioning Aquaponic systems in the Southern Cape at present, but we have had inquiries from all corners of the country, as well as the rest of Africa and the Middle East. We can be contacted at our blog Synaptoman or on aquaculture@knysna.sa.com or phone Kevin on 082-5546981.

We have also recently established a Tilapia Hatchery is Knysna using top quality broodstock from Stellenbosch University, and are able to supply local farmers with mixed-sex or high-yielding male-only fingerlings.

Regards

Synaptoman