What is Aquaponics and How Does it Work?

Aquaponics is a growing trend both for commercial farmers and urban greenies. Last month there were 74,000 Google searches for the word and according to a US report, the commercial industry is set to earn one billion dollars by 2020.

So, what is all the fuss about?

The simplest way to explain aquaponics is hooking up your fish tank to your veggie garden. In other words, it is a system that combines aquaculture and plants. The veggie garden is different to a typical soil garden - instead of soil, plants live in an hydroponics system that keeps the aquaponics system clean and healthy, and accelerates growth. Fish are placed in a tank and the waste they produce (yes, I do mean poo) is converted into nutrients that feed the plants. The plants then filter and clean the water, which keeps the fish happy.

There are many benefits of aquaponics over traditional gardens. In aquaponic systems, you will need just 2% of the water required for an ordinary garden. Additionally, you do not need to do any weeding, fertilizing or using of harmful pesticides.

One of the disadvantages often cited is that it very expensive to set up. However, as with hydroponic systems, you can customise your aquaponic garden to your needs- it can be as simple or as complex as you like.

What type of fish are suitable for aquaponics?

Large and commercial aquaponic farms use edible fish species such as perch, tilapia, barramundi or cod- essentially creating a 'double farm' of vegetables and fish. Luckily, home systems of with fish tanks of 300L and above can grow edible species too.The best species for home aquaponics with less than 300L or water are tough and adaptable ones such as goldfish, angelfish and guppies.

What else do I need?

When you first begin experimenting with aquaponics, it's best to start small. To make your own mini-system you will need:\n

• A location with sunlight for the plants
• A fish tank.
• A water pump.
• Plastic tubing.
• An air pump with air stone.
• A container for your plants.
• A growing medium such as perlite, coconut fibre or clay pebbles.
• A PH test kit, an ammonia test kit is handy too.
• Fish and plants.

How do I put it all together?

You can adapt any kind of hydroponics system to also include fish. Essentially, all that is needed is to replace your nutrient solution container with a fish tank instead. Using the above materials, you could create a Drip System, by making a loop of tubing coming from your water pump, poking holes into the loop and sitting it in the top of your plant container.\n\nYou could also use a Nutrient Film Technique, by pumping your fish water through PVC piping containing your plants; or a Deep Water Culture system, where your plants are suspended over the fish tank.

One of the quickest and easiest methods that we have discovered is to simply take a piece of polystyrene, cut holes in it and plant herb seedlings such as mint or cress into the holes. Then just float the whole thing in the top of your fish tank and watch them take off!

To find out more about how to build and maintain your own aquaponics system, take a look at our other articles.