Why Aquaponics?

While visiting my dear OzEarth friends in Holland, for the last time before they move home to their land in Tasmania, I was able to watch Murray Hallam’s DVD on Aquaponics, and I was hooked!

I have been concerned for years at the bizarre fishing policy of the EU, the wastage of good fish and the shortage of the popular species like cod; and as a fan of fish for food, I have been annoyed to find that I can’t afford to eat fish very often!

Another concern of mine, as we lay tied to life’s railway tracks, watching the approaching trains of climate change and peak oil, and wondering which will hit us first, has been the prospect of increasing food scarcity globally and the increase in food costs locally. To that end I have been growing much of my own food for a few years.

However, I am now at a turning point. As I become victim of the inevitable physical restrictions of advancing age, I have decided to make some changes. So I shall sell my house, and provide my son with a deposit for his house purchase from the equity. In return he will provide me with some minimal living space – perhaps a static caravan or granny annex – and some garden space. It is my hope that I shall be able to set up a small aquaponics unit, providing vegetables and fish for the family, possibly selling any surplus over the garden gate, and, after a learning period, running one-day courses for other people who might want to do the same.

That decision taken, I am now at the research stage (as well as the renovation stage, to bring my house up to saleable standard!) and to that end I start this blog, for my own benefit, to record the stages of my learning process as well as listing useful links on the subject of aquaponics.

What has become clear is that in UK this is very much an embryonic discipline. Most home aquaponics practitioners, as well as experts like Will Allen, are in the United States. There are a few in Australia, home of the inimitable Murray Hallam. There are almost none in UK, with the only link to expert advice I have been able to find being Aquaponics UK in partnership with Stirling University.

So, not being able to start doing it yet, I have been reading, and trying to get answers to questions: What kind of fish? Where can I get tanks? What type of system should I use? Should it be under cover? Endless questions, which in turn lead to more reading and then more questions.

My conclusions so far are these.

I would prefer Tilapia, because they grow quickly, they tolerate fluctuations in water quality and they are omnivorous. Carp – don’t fancy them! Barramundi – they eat each other (don’t blame them – they are very tasty)! Trout – they take 18 months to get to plate size.

So, Tilapia: on the down side, they are rather prolific breeders (although this can be dealt with in two or three different ways) and they need warm water.

Now as far as I am concerned, the warm water can be used as an advantage; this I discovered from The Polytunnel Handbook. Some people (including Will Allen by the way) use water as a means of stabilising the temperature in a polytunnel. If you have a polytunnel with a tank of warm water, it will dramatically increase the length of the growing season, with some vegetables growing all year round.

In Australia you can be fined many thousands of dollars for having a Tilapia alive or dead! In the warm river waters of Australia they overbreed and destroy the river ecology. But in our UK climate, there is no risk of that as they can’t survive below about 20°C and flourish at 24°C. Lettuce grows at an optimum temperature of 22°C.

The Polytunnel Handbook contains many useful hints and tips about types and uses of polytunnels (although aquaponics are not mentioned), and I became aware of the Keder greenhouse. This is a very sophisticated and good quality type of polytunnel, using a double skin covering with ‘bubble-wrap’ type insulation between the skins. They are strong and carry a ten year guarantee. They are also expensive, so I shall have to wait to see if I have enough money to indulge myself when I have sold my house!

What I would say as a summary at this point is that I am very worried about the future of both the planet and the UK. I don’t think that the politicians have come close to addressing the problems. So I want to start the process of increasing the resilience of my family. Of course, at this stage of the game they are pretty uninterested, and not really worrying, but I hope that as our situation starts to deteriorate seriously, they will see the potential of all this, and take sufficient interest to take over the running of it!