Agri Kultuur January / January 2018 - Page 21

Construct the Biofilter: Biofiltration is the conversion of ammonia and nitrite into nitrate by living bacteria. Most fish waste is not filterable using a mechanical filter because the waste is dissolved directly in the water, and the size of these particles is too small to be mechanically removed. Therefore, to process this microscopic waste an aquaponics system uses microscopic bacteria. Biofiltration is essential in aquaponics because ammonia and nitrite are toxic even at low concentrations, while plants need the nitrates to grow. In an aquaponics unit, the biofilter is a deliberately installed component to house most of the living bacteria. Furthermore, the dynamic movement of water within a biofilter will break down very fine solids not captured by the clarifier, which further prevents waste build up on plant roots in NFT and DWC. Construct the DWC Canals: Components Required: To prepare the outlet of the DWC canals, the following list of components would be required: Water Outlet 32mm x 1” Adapter Socket (Female Thread) 50mm x 25mm Reducing T-Junction Solvent Socket 50mm 90° Elbow Solvent Socket 50mm T-Junction Solvent Socket 50 x 1½” Adapter Socket (Female Thread) 1.5” Running Nipple 40mm PVC Lock Nuts 40mm Rubber Gasket 1” (25mm) Running Nipple 25mm Rubber Gasket 25mm PVC Lock Nuts 6 3 5 1 1 0 .5 2 2 1.5 6 6 each each each each each each each each each each each Water Inlet 25mm Ball Valve Single Union Solvent Socket 25mm T-Junction Solvent Socket 25mm 90° Elbow Solvent Socket 3 3 12 Each each each Cutting the IBC Tanks: • Remove the two horizontal steel lengths attached to the top surface of the IBC tank holding the inner plastic container in place. • The steel lengths are fixed with 4 star headed screws. Remove these four screws using a star headed screwdriver. Once the steel lengths are removed, pull out the inner plastic tank. • After pulling out the tank, it is recommended to paint the outer surface of the IBC liner black to prevent algae from forming. • Remove also the metal base by removing the screws. If there is no star key, cut the screws with an angle grinder. • Cut the vertical metal bars above the 2 nd horizontal framing with a grinder (see picture). The beds won’t be exactly AgriKultuur |AgriCulture even, one side will be slightly higher than the other side, but it makes very little difference in the actual system. • Once you have all the bars cut, you’ll have to cut the plastic. Use the frame as your guide and draw with a permanent marker around the IBC. Then, using the angle grinder, cut along the line and remove the cut piece from the top. 21