Both these systems are about growing vegetables, without soil as the growing medium, and supplying nutrients to the plants, via water only. This can be related to small scale production or commercial units. Our interest is to introduce it to small scale farmers and back yard areas, where good soil is scarce.
The growing medium can be sterile, such as sand, stone, gravel or water only containing the nutrients.
It is used in large cities where agricultural ground is far way and transport is a consideration. When transport is eliminated, it also reduces carbon emissions and helps reduce global warming. Aquaponics uses fish faeces as the nutrient for plants, by circulating the water, where fish live, over the plant roots.
The fish also breed producing protein, increasing food sources. Unfortunately, there are no indigenous fish within the CWBR ideally suited to aquaponics, so tilapia, as a hardy fast breeding and growing fish, are used. A permit is required for this. Commercial hydroponic farms use manufactured nutrients as a norm, but at the SLC we are using worm tea and castings mixed in the water, to showcase that hydroponics can be practised organically , either with fish or worm castings.The advantage to both these systems is that that they can be done on a large or small scale, and do not use huge amounts of water, as the water is recycled. It is also practical to use grey water for hydroponics.
Loss is either through evaporation or absorption by the plants, but none is lost into the ground.
Hydroponics can be done vertically as well, using many different containers, including recycled cans, gutters and plumbing pipes. This also demonstrates food production where horizontal space is limited. Using small inexpensive solar pumps, allows for this to be practised in rural as well as urban areas.