Aquaponics: A New idea for local food

A Presentation Summary

At the beginning of the year, I had the privilege to give a presentation to members of Transition Farnham (and Guildford) on my new found obsession – Aquaponics. Thanks for everyone who attended and participated in the discussion afterward. Hopefully it planted a few seeds (excuse the pun!) for some new ideas about how we can use this technology in a local, sustainable way.

The following is a summary of that presentation, describing what aquaponics is (or as I understand it!), why I think it’s such an exciting innovation, and my hopes for how we can use it locally, in line with the Transition Movement’s train of thought.

I will also touch on my own recent DIY endeavours into aquaponics – half the time, the best way to learn is to get stuck in.

I hope it is a useful introduction to the technology and sheds some light on what might be possible in our own communities.

What is aquaponics?

Tilapia in aquaponics system at the Biospheric Project

Tilapia in aquaponics system at the Biospheric Project

Aquaponics is the merger of aquaculture – the growing of fish indoors – and hydroponics – the growing of fruit and veg in non-soil medium.

It is a reciprocal arrangement between the two whereby each is mutually benefited.

The fish produce waste in the form of ammonia which by the power of chemistry, is broken down with some friendly bacteria to nitrates. These get absorbed by the plants taking in the nutrients, filtering the water and sending it back fresh as new to the fish to use all over again.

I never thought you could grow food in anything but soil so it was quite a revelation for me initially. I think it’s great to feel surprise again when you learn something new.

In theory it is a closed loop, synergistic system.

In practice it’s a little more difficult than that – factoring in the other externalities that go into it like electricity and fish feed – as in reality there’s no such thing as a completely closed loop.

But it was the general principle and simplicity of the model that drew me to it in the first place, and with this basis it’s quite flexible, for example, using different fish in the system. Tilapia, which I have, are most commonly used because they are the hardiest. They can live at quite high Ph variances, and are quite happy at high density stocks, but you could also use other fish like perch, and trout, but they are a little more precious.


The title, “new idea for food” is perhaps false-advertising as this isn’t a new technology as such. The Aztecs used this technology centuries ago, growing maze on reed rafts on lakes, and the Chinese are also documented as also doing similar 1500 years ago.

Currently it is being used more in community and commercial settings, but this is certainly still niche and not going to replace current agricultural practice anytime soon.

Benefits of aquaponics

 At an initial glance there are clear appeals to aquaponics over other methods. Some advantages include:

–          90% less water use than traditional soil methods (you only need to replace water taken by plants and through evaporation)

–          Higher yields – the roots don’t have to spread out and compete for nutrients as much as in soil so plants can be more densely packed.

–          Plants can be grown throughout the year (if grown indoors).

–          No artificial chemical fertilisers and pesticides.

–          Highly flexible – can be adapted to suit location and needs of individual, community or business.

Growing need for change

My interest in aquaponics is set within a context of a growing need for a better solution to the associated problems of modern life – whether it be climate change, inequality, resource depletion, environmental degradation, human exploitation, or poverty etc.

Presently, my particular focus is around food production and distribution, and principally how we create it sustainably in accordance with nature.

Food is obviously one core necessity for us all and it is an area which I believe we can increase our efficiency massively, so that we can adequately meet the nutritional needs of everyone on this planet – no mean feat!

Currently we’re sold the myth that we can’t feed the planet. You know the drill – 1 billion people are starving right now, by 2050 we’ll have 9 billion mouths to feed and the only solution is more intensive agriculture, turning to high yield GMO monoculture crops as our salvation.

Well, I just don’t buy that. The problem isn’t that we don’t produce enough food. Even with our current methods we already meet the calorific needs of everyone.

The problem is that we waste so much of it.

The Institute of Mechanical Engineers has recently reported that we waste around 30-50% of all food produced – much of this wasted in the production and transportation. Purely from a point of sustainability we can’t keep shipping in our food from all for corners of the planet.

The problem is also access to food.

In the UK context, when you look at food prices rising faster than peoples’ wages, as well as the cuts that are being made then you can understand why Guildford and Farnham now have four food banks between them.

Food security is a complex problem than just these two issues alone, but it’s clear to me that we need to change our food systems, and, ultimately, the economic system that underpins it. We can’t carry on as normal – but I’ll leave that rant for another day!

Bearing in mind all of the advantages, as described above, aquaponics has the potential for broad social benefits, making it easier for people to grow food, more cheaply, and closer to them.

London: The Farm: Shop

Farm Shop Dalston

So I was really excited when I stumbled upon this neat little project in Hackney called Farm: Shop.  The project is a collaboration between a number of community groups and Hackney council.

They’ve renovated an old terraced building – an old shop in Dalston – and installed an indoor urban farm with a mini-aquaponics and hydroponics systems. It also has a café where it sells the produce that it grows.

It’s a great little experiment because whilst it’s not going to set the world alight and solve world hunger, it is a new model of how Londoners can interact with their food and community, and maximise the available space.

The wider social benefits are that it’s a place where people can congregate, volunteer, and learn how to live more sustainably.

It also provides a model as to how the local community can take ownership back over the means of production of their food.

For me, I would love to see something similar on every street corner across the country.

Essex Aquaponics

DIY aquaponics system

DIY aquaponics system

Seeing this system in action inspired me to try it out for myself, so without the space myself (I’m a fairly recent immigrant to Guildford) I commandeered my parents’ garage in Essex.

There’s nothing like getting stuck in to learn by experience – or should I say trial and definitely a lot of error. It turned out to be a bit trickier than I first thought but with a bit of tinkering along the way we have had a good 6 months growing basil, perpetual spinach, tomatoes as well as a bumper crop of peppers, to name a few.

Give it another week and the Tilapia should be ready to eat!

Biospheric Project

Biospheric Project

Setting up my own system was always an experiment, and I’ve been keen to scale up something larger on a community basis within Guildford/ Farnham.

To get an idea of what could be possible I ventured up to Manchester to visit the highly impressive Biospheric Project.

Located in a disused warehouse in the middle of Salford, it comprises of a number of different elements, including aquaponics, vermiculture, and a communal forest garden. Each of these elements is connected in one bigger system.

The project team, led by Vincent Walsh, was set up to see how such a system could work in an urban environment. All indications are looking good and an evaluation will be published in Walsh’s PhD paper on the project – I look forward to the results.

Future plans: Guildford/ Farnham

With all this in mind I am keen to getting cracking and setting up a project in Guildford. What this will look like is still a bit vague, but in the first instance it will be about furthering the knowledge of aquaponics locally, and we can develop the next steps in due course.

I would like to think a future project might try to address the rising need of food banks locally in Guildford and Farnham, and help them implement a community owned, highly sustainable, and virtually free, food system.

Perhaps, a project will develop which looks to generate a cooperative of local aquaponics growers to sell at the local farmers market?

Let’s see where it take us.

If you would be interested in getting involved in any way please do email me and I will look to convene a follow up discussion in due course.

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