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Aquaponics a Sustainable Food Source

Aquaponics is a food production system combining aquaculture and hydroponics in a symbiotic environment.

Wow! Better explain some of that.

A food production system: growing vegetables and rearing animals for eventual human consumption.

Aquaculture: Fish farming. The farming of aquatic organisms like fish, shellfish and underwater plants.

Hydroponics: Growing plants without soil. All plant types can be grown in inert substrates as long as there is water and the water contains the right plant nutrients.

Symbiotic: A relationship of mutual benefit. A close and long-lasting relationship between different organisms that usually benefits each organism.

Aquaponics is not a new food production system.
The Aztecs grew plants on Aztec-built islands. The plants being fed from mud and waste material.
The Ancient Chinese allowed fish to swim amongst the rice plants in the rice paddies.

But it wasn’t until the late ’90’s that academia became interested and proper research undertaken.

How Does Aquaponics Work

In nature organic matter decays and mixes with the soil. Bacteria breaks down the decayed matter into nitrites and nitrates that plants use for food.

Aquaponics takes advantage of the nitrogen cycle in nature. Fish waste is broken down into nitrites and nitrates which are then fed to plants. As long as the fish are fed and the water chemistry is correct the symbiotic relationship flourishes.

Combination of Aquaculture and Hydroponics

Aquaponics uses aquaculture for raising fish and hydroponics for growing the plants.

The only input to the system is fish food.
The fish eat the food, excrete the waste into the water. The extrament is converted into a nitrites and nitrates that the plants can use to grow.

Three main components make up an aquaponic system: Plants, fish and bacteria.

Aquaponic Plants

Many plants thrive in an aquaponic system, however you need to select the right plants based on the maturity of the system and the number of fish in the fish tank.

Green leave vegetables like chinese cabbage, lettuce and water cress grow well with medium nutrient needs.

Tomatoes, cucumbers and peppers need high levels of nutrients and a large number of fish in the tank

Aquaponic Fish Types

Fresh water fish are the most common fish for your aquaponic system.

Tilapia the most popular because they can tolerate crowding and when they are grown they can be eaten.

If you don’t want to eat the fish then koi and goldfish can be kept.


Nitrification, the conversion of ammonia from the fish effluent into nitrates is the reason why aquaponics works.

nitrogen-cycleNitrosomonas are bacteria that converts ammonia into nitrites.

Nitrobacter are bacteria that converts nitrites into nitrates.

It’s the bacteria that makes the whole system work.

The waste produced by the fish is consumed by the bacteria converting it into plant food, the plants eat the plant food in the water helping to keep the water quality safe for the fish to thrive.


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