Aquaponics, refers to any system that combines conventional aquaculture (raising aquatic animals such as snails, fish, crayfish or prawns in tanks) with hydroponics (cultivating plants in water) in a symbiotic environment.

A portable aquaponics system with watercress - wikimedia - wikimedia

In normal aquaculture, excretions from the animals being raised can accumulate in the water, increasing toxicity. In an aquaponic system, water from an aquaculture system is fed to a hydroponic system where the by-products are broken down by Nitrifying bacteria into nitrates and nitrites, which are utilised by the plants as nutrients, and the water is then recirculated back to the aquaculture system - wikipedia

As existing hydroponic and aquaculture farming techniques form the basis for all aquaponics systems, the size, complexity, and types of foods grown in an aquaponics system can vary as much as any system found in either distinct farming discipline.

# Live components

An aquaponic system depends on different live components to work successfully. The three main live components are plants, fish (or other aquatic creatures) and bacteria. Some systems also include additional live components like worms - wikipedia

A Deep Water Culture hydroponics system where plant grow directly into the effluent rich water without a right medium. Plants can be spaced closer together because the roots do not need to expand outwards to support the weight of the plant.

Filtered water from the hydroponics system drains into a right tank for re-circulation.

Nitrification, the aerobic (aerobic organism) conversion of ammonia into nitrates, is one of the most important functions in an aquaponics system as it reduces the toxicity of the water for fish, and allows the resulting nitrate compounds to be removed by the plants for nourishment.