Aquaponics combines two conventional methods in a harmonious relationship: Aquaculture (the farming of fish) and Hydroponics (soilless plant growing) to produce a more sustainable and efficient loop system.
The fish produce waste (Ammonia – NH4+), the waste is then converted to fertiliser (Nitrates – NO3+) for the plants to consume, which in turn removes the toxic compounds cleaning the water for the fish.
The key to aquaponics lies in mimicking natural ecosystems, more specifically the nitrogen cycle, which is driven by nitrifying bacteria (Nitrosomonas spp. and Nitrobacter spp.).
Because of the symbiotic nature of hydroponics and aquaculture, it solves major problems with each method on their own: disposing of toxic waste from aquaculture and sourcing of quality nutrients for plant culture. The process of recycling of nutrients is a key aspect when forming a permaculture-based existence.
- <90% less water usage
- 60% less space than soil production
- <50% faster growth rate
- consumes around 75% less energy than traditional farming
- provides year round harvests
- can be performed organically
- allows fish to be added to the produce list as well as plant based foods
All of these facts make it a great solution for any scale of production, from small home aquaponics kits, right up to commercial systems.
- Deep water culture- A floating raft structure e.g. polystyrene is placed on top of a nutrient rich reservoir (usually a sump), into which the crop is planted
- Media bed- Uses an inert planting substrate. A flexible technique that can use a flood and drain (cycle) or flow through configuration
- Nutrient film technique- Uses a shallow flow of nutrient rich water. It is pumped through a network into which the crop is planted. However, it is less commonly used in aquaponics than hydroponics due to the presence of solid waste.
- Vertical aquaponics- Nutrient rich water is pumped to the top of a grow tower; it then drains down over the root network
Using correct design and following certain rules, an aquaponics system may be put into nearly any space or environment and potentially can grow almost any crop year round.
Although these are the primary methods, the most successful systems incorporate several methods to ensure the most efficient nutrient and water filtration.
Like methods such as fungiculture, evidence of fish farming and soilless production stretch back thousands of years but serious research into aquaponics only began in the late 1970’s demonstrating the scope and room for further progression in this field. Safe to say, it is the method of the future! For use in education, aquaponics is a brilliant case study/model of natural processes and both inspires as well as teaches values such as: sustainability, sciences, responsibility, environmental ecology and life cycle.