Aquaponics, Food for a Hungry World

Aquaponics, Food for a Hungry World - I spend a lot of time thinking about this, although I won't be doing anything physical on it until next year. I am not writing this blog for anyone else - just me! I don't mind if no one else reads it at all, but it helps me to keep a record of my progress and my thinking.

But if you do decide to read it, feel free to comment!

Tuesday, 11 October 2011

Birthday Present for Myself!

I had my birthday on Sunday. Some family members made more of a fuss than I thought was warranted but it was very enjoyable - I was given a very useful digital SLR camera - something I always assumed that I would never be able to afford - and a pleasant lunch and a delicious supper.

But for myself, I bought two books. One was a recipe book by Hugh Fearnley-Whittingstall called River Cottage Veg Every Day and consists of recipes which do not include either fish or meat. It is not written specifically for vegetarians; it is simply an attempt to get people eating more vegetables. I can see it becoming my cooking bible once my aquaponic unit is up and running.

The other book I bought was one I pre-ordered months ago: Aquaponic Gardening by Sylvia Bernstein. This has only just come onto the market, and I would consider it essential for anyone interested in the subject but particularly the beginner. It is written in an easy-to-read and entertaining style, which is not in the least patronising, and as far as I can tell so far, covers every aspect of setting up an aquaponic system making due allowance for different climates and for those of us used to working with metric measurements.

Although I don't expect to get started with my set-up until next year, I am finding this book interesting and instructive, and as a result of reading it I expect to be better equipped to get going as soon as I have the premises!

Thursday, 4 August 2011

Spreading the word

As you might expect, I have been talking about my plans with some enthusiasm to anyone prepared to listen. My son has had an offer accepted on the house he currently rents, and so we have discussed how to turn the garage into an annex for me to live in, complete with an outside area, where I hope to put up my 4M x 3M Keder greenhouse. There is a slight conflict at the moment because he is hoping to build an extension which could encroach on the greenhouse area - but I hope this can be resolved.

However, assuming that problem can be resolved, the situation looks promising and the deal can go ahead as soon as I have finished renovating my house so it can be sold.

Meanwhile, I went to a conference on renewable energy the other day. There were many presentations, most of which I had heard before, and there were a quantity of exhibition stands, which dealt with wind turbines and PV panels for the most part, with a smattering of solar thermal and biomass products. I saw nothing on wave or tidal energy, which in Cornwall, with sea on three sides, is disappointing. I was interviewed briefly by a couple of 'media' students who were being paid for by the sponsors (the local authority) to gather feedback, and was happy to say that I thought the conference was very worthwhile if only for the opportunity it presented for spreading the word about environmental matters and green energy.

On the matter of spreading the word, I was mentioning my aquaponics plans to a friend and her colleague, who suggested that I should share my ideas with the local Transition group. She and her colleague are both active in the Transition movement, and seemed unconcerned that I have, as yet, no practical experience whatsoever! But I am quite capable of talking about aquaponics at length, and can intersperse my chat with various video clips, so I will be happy to accept the challenge!

Sunday, 17 July 2011

IBC tanks

I have spent a bit of time on line, particularly Ebay, looking for a source for IBCs at a reasonable price, reasonably close by my home, and not contaminated with something nasty. I am planning to build my system on a shoe string, as well as looking for the best use of space in a 4M x 3M Keder house, and I reckon I can use an IBC for the fish tank, a plastic water tank for the sump (planted in the ground and packed in insulation sheets) and five second-hand bath tubs for grow-beds. The sump will be covered so that it can be walked on, thus saving space.

But as for the IBCs, I got sick of looking! I was talking to a friend of mine who processes organic food, and mentioned my frustration - whereupon he said that he gets them all the time, and that his have only been used for sunflower oil. And they are only 5 miles away!

I spoke to my son about all this, and he told me that our local all-purpose hardware store also stocks them, quite cheap!

We are inclined, these days, to assume that the internet provides us with all the answers. Perhaps if we looked closer to home at the outset, fewer small businesses would be going out of business!

Sunday, 26 June 2011

Breeder Colonies

I have been reading about a breeder colony: in other words a separate tank in which to breed new fish. The website where I found the information, Tilapia Farming At Home, is a US based website, and the suggestion is that by producing hybrids from a male O. Hornorum and about half a dozen O. Mossambica females, you produce 98% male offspring, thus avoiding the problem of over-breeding in the fish tank. In this website, photographs indicate that the offspring are a reasonable size and shape!

I need to get a second and third opinion about this, as well as checking availability of these varieties of Tilapia - but it sounds like a plan!

Monday, 20 June 2011

System Design

I've been thinking a lot about how to design a system in a 4m x 3M Keder house. I am coming around to the idea from Murray Hallam, that perhaps a sump is a good idea, mainly from the point of view of relative levels. The fish tank could sit on the ground, and the grow beds could be fairly low (which I would prefer, for access to climbing plants) especially if the sump was sunk into the ground. It could be completely insulated to help maintain temperature, and the growbeds could be insulated too. Another plus is that much of the pipework could be run underground, which, especially if lagged, would also help to retain temperature.

I needed to find out how big the sump needs to be, so I asked Charlie Price about the medium/water ratio in a grow bed. (He said it's about 2/3 to 1/3) I have worked out that if I have five bath-tub growbeds, I would need a sump with a capacity of around 450 litres.

I have asked Murray Hallam if I would be able to use the sump as a breeder tank - which could solve the fish stock problems. I read that you can have a breeder tank for Tilapia, and if you have a male of one type (specified) and I think five females of a different type (specified), the offspring are 98% male, and it occurred to me that these could live in the sump!

Now I have to find a source for a 500 litre tank of the right shape, preferably without buying two IBCs!

Thursday, 16 June 2011

How Safe is Aquaponics?

The recent e-coli scare in Europe (the scare, but not the infection, has spread to the USA) has pointed up the question of safety in vegetables.

Over a couple of years, in the States, a comparison between green vegetables purchased in grocery stores, and those grown aquaponically, showed that the latter were pathogen free – in other words, the aquaponically grown vegetables were 100% safe.

However, ironically, again in the USA, aquaponically grown food cannot qualify for a Food Safety Certificate. The reason for this is the book of rules, and specifically two parameters which cannot be complied with. The disqualifications arise because of the presence, first, of animals in the growing area, and second, of untreated manure in the growing area. The book of rules does not take into account the fact that manure from cold blooded animals cannot transmit these diseases.

In the UK we have the Soil Association, and here we come across a similar contradiction – food cannot be considered organic if it is not grown directly in, and harvested from, the soil. And yet most of us are aware of organic farmers who would not eat their own produce, because of the pesticides they are allowed to use, and which would certainly kill the fish!

Is it time to re-evaluate? Well, I guess that’s up to the Soil Association. But I confess to feeling that the current definition of ‘organic’ is out of date and therefore lacks credibility. If you are growing in soil, you can gain organic certification without improving the nutritional value of your produce, depending on how you treat your soil; and of course it does not preclude the possibility that the produce could transmit e-coli. If you are growing aquaponically, you cannot do anything which might damage your fish, and if the fish survive, I reckon I will too!

So I feel enthusiastic about the proposed Aquaponics Association in the USA, whose purpose will be to 'preach the gospel' of aquaponics and perhaps persuade the certification bodies to adjust their criteria. Of course, the US, particularly Hawaii, and Australia, are way ahead of the British in the field of aquaponics - but we must do our best to catch up.

Saturday, 28 May 2011

Garlic Spray

I looked at my one tomato plant in my greenhouse today, and was surprised and annoyed to see signs of blight - so early in the season, and after so little rain. So I decided to try mixing a garlic spray. I used most of the very small garlic cloves from last year's harvest, mashed them with a pestle and mortar, and followed the instructions - halving the quantities. I still have over 2 litres of the stuff left, and the recipe says it must be used fresh! Also my house stinks of garlic!

Whether it will deal with the blight or not remains to be seen!

16th June: It Works! After removing a couple of slightly blighted leaves and spraying with the garlic, there have been no further signs of blight! Next question - can the liquid be frozen and keep its fungicidal properties?

Wednesday, 18 May 2011

Fish Stocking Levels

I have found a lot of very useful information at The Aquaponic Source. In particular, though, I was looking at fish stocking levels, and found an apparent difference between the advice from Murray Hallam and the advice from Sylvia Bernstein, so I emailed Sylvia to get some clarification. These two ‘aquaponistas’ bridge the gap between Australia and the US, and Sylvia explained that there is no difference in the two sets of advice, one being based on numbers and the other on weight. I watched Hallam’s video (the short version) again and realised that his ‘1 fish per 10 litres’ refers to fingerlings. Problem solved.

I have often noted that aquaponics is not a popular practice in UK. In my search for information, I have not found a UK centred aquaponics book. (perhaps Stirling University could look at filling this gap!) What I did find, last time I checked with Amazon UK, was ‘Aquaponic Gardening: A Step-By-Step Guide to Raising Vegetables and Fish Together’ by Sylvia Bernstein, and having browsed her website, The Aquaponic Source, extensively, I realised that this is probably the most useful book I could find on the subject although it is based on US practice. Sylvia was surprised when I told her I had ordered it as it doesn’t come out until October! But I have pre-ordered it and will have to be patient!

One reason I have for looking at stocking levels in particular is because I have seen a house where I may end up living, and there is slightly less floor space than I had hoped for. The situation would otherwise be pretty good but I have to work out how to fit in my aquaponics project – hence the calculations! But I am sure it can be done!

Wednesday, 11 May 2011


I followed up the rhubarb pesticide question with the website where I found the recipe. This was the emailed response:

I would imagine that a high enough concentration of rhubarb leaf pesticide in a small volume of water could harm fish but in a garden-pond scenario with a small dose that there would be little risk. However, by avoiding spraying the pesticide into the water itself you will avoid any risk to the fish.

di Jonathan Radford

So I guess that used with care, it should be OK.

I have received the brochure and a sample from the Keder greenhouse people, CLM. They look like everything I could want, but the prices are high enough to contract the sphincter muscles! I shall have to downsize my expectations – or possibly live in one! But they look fabulous. Exactly what I need.

Pest Control!

The issue of pest control in organic gardening becomes even more important when considering aquaponics. Will the pest control used harm the fish? Will it make them inedible? What pests might harm both plants and fish?

Apparently snails and birds must both be kept away from the fish, as they may carry parasites which can also attack fish. Does that include slugs I wonder? What if you feed a slug off your lettuce to the fish?

I found a DIY aquaponics unit on Youtube where the legs of the grow-bed stand were stood in containers of water to avoid slugs climbing up. It seems to me that it would be wise to prevent access to the unit for slugs and snails, and under cover, birds should not be a problem.

There seem to be a number of pesticides which can be made from plant extracts, and the most widely spoken of is garlic, which is suggested by Murray Hallam in his DVD. Another is rhubarb leaf, and I am still trying to establish if this is harmful to fish. My new best email friend Charlie, at Aquaponics UK, also mentions elder, and chilli. I quote here his responses to my email query about the use of rhubarb.

I also notice frequent mention of soap spray – with the warning that it should be ‘soft soap’, e.g. washing-up liquid, not detergent. This seems to make life difficult for aphids, as well as enabling any pesticide to stay on the leaves.

Of course we should never forget that all this produce is to be eaten by US!

“Hi Tim,

I’m afraid I’m not sure (even though 6 years of my PhD research was focusing on aquatic ecotoxicology or replacements to organophosphate pesticides), i don’t have a scoody doo, I’m afraid.
i have made formulations with rhubarb and elder which both worked great, but i have only used them in soil... but I’d be very interested to hear how you get on, please keep my updated...

Garlic, and soap sprays are well proven options... and ones we use with good effect, but you make reference to a Keder house, so I’d suggest making sure they don't get in and if they do, then establish a healthy population of beneficials... “

“Yes, we've used garlic, chilli, and soap sprays and they have been fine, ultimately it’s a foliar treatment and providing the surface area of your growbeds, if media, is not wet, which it shouldn't be, then any active ingredient should volatilise before it’s an issue.. if indeed it would be in the first place, similarly with rafts.
I would think it would be fine, and next time I get a pest issue, I’ll definitely try it... and keep you posted too

best wishes

Monday, 9 May 2011

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!