Aquaponics combines growing fish and vegetables together in the same system to provide an ideal solution for sustainable gardening and food production. It uses less energy, water and chemicals than traditional soil gardening, and the fish waste provides nutrient rich fertilizer for the plants. In addition, it has a number of educational and environmental benefits for the home or community gardener.

The main components of an aquaponics system are fish tanks, rearing and growing beds, and biofilters or bioreactors. The grow beds need to be made of non-toxic materials that can support fish and plant growth. They should be able to be washed and sterilized to prevent disease, as well as to retain the needed porosity for healthy nitrifying bacteria. Growing beds can be built with clay pebbles, expanded shale, gravel or other inert material.

A Beginner’s Guide to Aquaponics: Growing with Fish

For an aquaponics system to work, there must be a way for the fish waste to be converted into plant nutrients that are absorbed by the roots. The process requires the help of nitrifying bacteria, most commonly the species Nitrosomonas and Nitrospira. These bacteria consume ammonia and convert it to nitrites, which are absorbed by the plants. The plants then convert the nitrites into the necessary nitrates for growth through photosynthesis.

Aquaponics systems have the added benefit of reducing the strain on limited freshwater resources, especially in areas that suffer from drought or other climate conditions. The closed-loop design of the recirculating fish tank and growing bed system conserves water by minimizing evaporation, while providing nutrient rich plant fertilizer with little or no additional input from chemical fertilizers.