Backyard Aquaponics: Sustainable Living?


Imagine growing Barramundi in your own backyard?

Backyard aquaponics is the hybrid lovechild from those that espouse hydroponics and those that sermon us on aquaculture. It’s a system that marries the two and intertwines their relationship bringing to bear a sustainable gardeners offspring that we’ll call – Utopia!

Aquaponics is a system where aquaculture (a renewable fish farming method) and hydroponics (a renewable vegetable farming method) are built together to complement each method’s strength and weaknesses.

The downside of aquaculture is dealing with the polluted water. Ammonia rich it will inevitably starve the fish of oxygen if it’s not processed and purified. The problem with hydroponics is that it requires vast nutrients to supplement the feeding of plants.

Aquaponics takes the two weakest links and marries them together to produce a system that purifies the fishes water and feeds the hydroponically grown vegetables.

In a nutshell, how does backyard aquaponics work?

As previously mentioned, the fish tanks become high in ammonia. This water is then filtered through a gravel bed where a bacteria has been cultivated and this bacteria turns the ammonia into nitrogen. The plants grow in the gravel beds and use the nitrogen to grow. The water is then returned to the fish pond clean and aerated, free from the heavy nutrients.

How do I set up aquaponics in my backyard?

While the backyard aquaponics process sounds complicated, and obviously expensive, it doesn’t have to be. The guy who inspired me to begin planning an aquaponics system, Joel Malcolm, built his system from scrounged materials and produced a working process for very little money. Obviously, you can spend heaps if you desire.

The basic construction relies on a fish tank and a gravel bed for the vegetables. Water needs to circulate between the two via a pumping system and the operation needs to be protected from the sun and hungry birds.

More information can be found via Joel’s site with an offer to buy his book and DVD.

What fish and vegetables can I grow?

Fish: Any freshwater fish species that are either local to your own area or that you can source readily from around the globe. This is also the same with shellfish and crustaceans. So, the possibilities are endless. You could be growing large barramundi with small freshwater cod, mussells and even some marron in the same tank giving your family diversity in what they eat.

Vegetables: Any vegetable that you can grow hydroponically can be grown in this system. Tomatoes, lettuces, carrots, beans, beets, potatoes, cabbages and the list goes on.

Can a backyard aquaponics system feed my family?

This is the most important question when considering whether to invest your time, effort and resources into a process such as this. If it only produces a few vegetables and a handful of fish then the process is flawed because the energy required (initially) is more than it takes to grow vegetables naturally.

Joel reports that his 4m x 8m (13ft x 26ft) plot harvested 50kg (100lb) of fish and 100kg (200lb) vegetables within 6 months. Therefore, if a family of 4 (2 adults and 2 children) ate 600gm (21oz) of fish every third day this would easily provide for them.

Why do sustainable gardeners need to employ aquaponics?

If you’re really serious about permaculture then backyard aquaponics is the new frontier in environmental safeguards. Sustainable living can only occur when we replace the most of our normal consumption with products that we create ourselves. This process produces vegetables in ways that we’ve done before but adds another dimension to create a meat source that even most vegans find attractive.
And it can all be done in your own backyard.

Photo source: Jack Parkinson Pics