A recent job advertisement for a tilapia farm manager stated: “This is a position for someone who is willing to do everything: building, welding, vehicle and pump maintenance, fish handling, etc., so you need to be jack-of-all-trades, and master of several. In other words, it is not a job for the guy who wants to play golf on Wednesday afternoon and drive a BMW ... but if you want a head start in tilapia culture, this offers immense opportunity” (Nicholas James, ichthyologist and hatchery owner).
One of our committee members, Lance Quiding of Integrated Aquaculture (BH34, R560) agrees. He has an in-depth knowledge of this method of farming and actively practices aquaponics. The attached photographs are from his aquaculture and aquaponics farm here in Hartebeestfontein. He agreed to send a short article on auaponic farming (below):
Aquaponics is the farming of fish and plants in a closed, recirculating water system. The waste from the fish is the nutrients for the plants, and the plants in turn, remove these nutrients from the water, purifying it for the fish. The fish waste is used to grow a plant crop that becomes a second income stream for some pioneering farmers or simply an amazing soilless way of keeping your kitchen stocked with veggies. There are four methods of aquaponic farming to choose from:
The first and most popular is the ‘Flood and Drain’ technique: This is where the plants are grown in an inert media (stone aggregate, shale, expanded clay, etc.), and the water floods and drains by means of a flow-out system. As the water floods and drains, the roots are exposed to oxygen and nutrients.
‘Deep Water Culture’ (DWC) is method number two: Here, the plants are placed on a floating raft, and the roots grow suspended in the water from the fish tank. Additional aeration is required to ensure that the roots get sufficient oxygen. Any grow bed can be used as long as it holds water and is best suited at a depth of 300mm.
Option three is the ‘Vertical’ technique: Here, the plants are grown in a substrate in vertical towers. There are several different designs of towers, and it is an extremely good use of limited space.
The final method is the ‘Nutrient Film’ technique: This is a horizontal pipe or tube where the roots grow in a film of flowing water cycled from the fish tanks.