The easiest definition of Aquaponics is the blending of aquaculture (fish rearing) and hydroponics (the soil-less growing of plants) that rears fish as well as plants together in one enclosed system. Wastes from the fish offer a natural food supply for the plants, and the plants help in naturally filtering of the fish water.
The other participants in the system are microbes, commonly known as nitrifying bacteria. These bacteria help in converting ammonia from fish waste into nitrites, and later into nitrates for plants use. Solid waste is also converted into vermicompost that is also consumed by plants.
In merging both hydroponic and aquaculture techniques, aquaponics capitalizes on their advantages and gets rid of the downsides of each.
Types of aquaponic system.
There are three main types of aquaponic systems that are commonly used today. They include:
- Media-based aquaponic system.
- Deep water culture aquaponic system.
- Nutrient Film Technique.
Let us now look at the different types of aquaponic systems listed above.
Media-based aquaponic system.
The media-based aquaponic system involves growing crops in inert growing media like extended clay-based pellets or shale. The growing media offers both the organic purification (transformation of ammonia to nitrates) and physical purification (getting rid of solid wastes) in the same system. Media-based systems are ideal for home and hobby size techniques to help grow an array of crops. Most importantly, big fruiting crops do very well along with herbs, leafy greens, and other types of plants.
Deep water culture.
Deep water culture also known as raft based growing, makes use of a foam raft which is floated in a water channel filled with water rich in fish effluent and has been filtered to remove any solid wastes. Plants are then put in holes inside the raft and the roots are left to hang freely inside the water. This technique is most suitable for planting salad greens as well as other quick growing, comparatively low-nutrient crops. It is usually most commonly utilized in bigger commercial-scale systems.
Nutrient film technique.
Nutrient Film Technique aquaponic systems work by streaming water rich in nutrients through narrow troughs, for instance, PVC pipes. Crops are then placed inside holes drilled in the pipes and the roots are left to dangle freely in the flowing water. As the water passes through the plant’s roots, it is filtered and pumped back into the fish tank. In this system, the plants benefit from nutrients supplied by the fish wastes while the fish benefit from filtered water freed from ammonia by the plants. This system works well for crops that require little support such as strawberries. This system is also perfect for saving space as it can be hang on ceilings above other planting areas.