Backyard Aquaponics - 24 Feb 2012

We were fascinated to see our friend, Augustine, operating an aquaponic system successfully right in his home garden. Aquaponics combines aquaculture (fish) and hydroponics (plants). We then googled to find out more about this new field. An eye-opener for us especially the children.

An organic partnership in aquaponics:-

• the fish provides the waste nutrients to support plant growth and
• the plant growth helps to maintain water quality and provides food for the fish

Augustine has both concrete tank as well as fibre glass tanks for his fish. He is not trained in this field, but he learned it all from the Internet.

He has more than 300 fish, both ornamental (eg koi) and edible types, such as tilapia, catfish, baung, kelah, soon hock and krai. Waste nutrients from the fish must be filtered out of the water. To reduce the toxicity of the water for the fish, the water will pass through grow beds, which are simple filtration systems consisting of gravel and worms.

A brilliant way to deal with solid build up in aquaponics is the use of worms, which turns the solid organic matter into a form that can be utilised by the plants.

An aquaponic system is like a mini eco-system. Without an effective means of maintaining water quality, nothing will work at all. It is very organic, there's no chemical input, no regular water volume changes, no complex mechanical filtration and water purification equipment. Everything required to maintain water quality has to be achieved within the system, not by technological equipment.

Natural fertilisers from the fish waste for plant growth.....
Plants are grown in grow beds (which are the filtration systems) and water is pumped from the fish tank into the grow beds, draining through the gravel, and back into the fish tank. The water can be reused and only need to be replaced when it is lost through evaporation.

Different types of plants growing in a symbiotic environment like lady's fingers, tomato, leafy vegetables, herbs, spring onion etc. The plants are also natural feed for the fish so there's no need to buy any chemical fish food.

The submerged roots of the plants provide food for the fish.... so no need to worry about feeding the fish when on holidays!

But more importantly, the roots provide a large surface area for the accumulation of bacteria. Bacteria is key in the conversion of ammonia from fish waste to nitrate, ie the nitrification process, in order to reduce toxicity in the water by allowing easier removal of nitrate through absorption by the plants.

Natural composting from kitchen waste.......

 Other healthy plants that benefit from the mini eco-system......

Producing food from the garden.......fresh steamed tilapia, and because these fish fed on organic plants, they're very tasty indeed. Food for thought - should we attempt to start this small scale aquaponics in our backyard!!!!