DWC

The DWC, also known as the raft method, is the technique that we are using for our Oceansing aquaponics systems here at Metro Farm. It involves cutting holes in styrofoam insulation boards to secure the plants and allow the roots to be suspended in the water. Net grow pots are placed in the holes and filled with sponge media as plant substrate. Because of the boards, the grow beds are required to be larger than the other two methods mentioned below. This is beneficial for stress reduction and to avoid potential problems regarding water quality in the fish tank.

The DWC method is the method that is most promising for commercial and mass production , because the boards can cover a large amount of space and once the plants are harvested, the boards can be reused for another cycle of planting. Because this method can be implemented on a large scale, it is perfect to help tackle the global issue of food insecurity.

NFT

NFT is more widely used for hydroponics. It involves growing plants in narrow channels, allowing for continuous but thin flow of water, which gives more oxygen and a constantly new supply of nutrients. This method though is limited in that only certain small plants, without large roots, can be grown in the system because of the high risks of clogging the narrow channel. The organic waste from fishes also creates potential points for clogging, so careful consideration must be taken. Due to risk of clogging, this method is not widely used in aquaponics systems. The NFT method requires constant maintenance including cleaning the piping on a consistent basis and only a small set of plants can be placed in this aquaponics design.

Media Bed

The media bed method consists of growing plants in a large container filled with media, which can range from gravel to perlite. This method is the one with the fewest components, as the solid waste is broken down throughout the media, removing the need for an extra buffer filter. However, this system does not produce a maximum output of plant growth. The NFT and DWC method produce at a faster rate because they have additional components. This method is good fas a hobby rather than a commercial scale unless developed further.