Oct 09

Recirculating Aquaculture Systems Bible

recirculating aquaculture

Recirculating Aquaculture by MB Timmons and JM Ebeling

This book is the ‘recirculating aquaculture Bible’. It contains everything you need to know about recirculating aquaculture, in tanks.  Aquaponics systems are a form of recirculating aquaculture systems, that use hydroponic beds full of vegetable crops as the biofilter for the fish farm.  This is true whether you are using tilapia as your stock fish or some other species such as trout. This form of fish farming is very sustainable aquaculture.

How to breed and keep fish commercially.

The various ways of keeping and breeding commonly farmed fish such as tilapia (oreochromis spp.)  in these aquaculture systems are described in detail.

Technical details and explanations.

It is a heavy tome full of all the technical details and explanations you could wish for.  It is used as a textbook on aquaculture in university agricultural science courses.  It is a standard required textbook on most high-level aquaculture courses, including aquaponics courses.

The science of Recirculating Aquaculture

If you want to know about the scientific basis for recirculating aquaculture in tanks of water, and tilapia husbandry, here it is. All the biology, physics and chemistry involved are described here in detail.

The tanks and plumbing.

If you want to know about the plumbing of these recirculating aquaculture systems (R.A.S. systems) then it is explained here.

How sustainable is it?

If you want to know how sustainable aquaculture in recirculating aquaculture systems can be, you can get down to basics with it here.

recirculating aquaculture systems

Fattening tilapia.

Tilapia feeding schedules, and the results of decades of aquaculture research on how to get these fish to grow to standard and to schedule, are described.

Sustainable aquaculture.

Recirculating aquaculture systems can be easily included in any sustainable aquaculture project as part of a sustainable farming business.

Science training required.

You will, however, require some previous science training, this is not for complete beginners. Sustainable aquaculture requires some previous experience of keeping fish and running a market gardening operation successfully as a business to prosper.

Aquaculture reference manual for farmers.

However, having read this book, and having it to hand as a reference manual, can only help you understand the advantages and the risks of sustainable aquaculture and running aquaculture systems as part of your farming enterprise.

Different from extensive aquaculture.

Sustainable aquaculture using recirculating aquaculture systems is quite different from extensive aquaculture farming in ponds. The environment in ponds is not as controlled or water-efficient as that in recirculating aquaculture systems. All the inputs in recirculating aquaculture systems are far more controllable and usually less than in extensive aquaculture.

Closer control on aquaculture inputs.

For instance, you can far more closely control your tilapia feed rate in recirculating aquaculture, and get more weight of fish for your feed dollars. Decades of aquaculture research have gone into this book to prove that this is so.  To find out more details on how this is done, I suggest you invest in a copy and read it! Click here for Recirculating Aquaculture or on the picture below to obtain a copy/

recirculating aquaculture

Recirculating Aquaculture By MB Timmons And JM Ebeling

Jul 05

Aquaponic System Rules Of Thumb.

floating raft aquaponics system

Simplified diagram, floating raft aquaponics system.

When setting up an aquaponic system, there are some definite rules of thumb as to how this should be done. I thought it might be useful to codify them into a list.

However, this is what happened when I tried…

  • Never use tap water straight from the tap (faucet in the US) in your aquaponic system. It kills fish since it is full of chlorine and/or chloramine. Age it for 48 hours to get rid of chlorine. You need a water conditioner for aquariums to get rid of chloramine.
  • Make sure the water is the right temperature for the species of fish you are using.
  • Make sure the pH of your water is close to 7.0 (neutral).
  • Make sure you have the right volume of aquaculture system to hydroponic system.  This should be AT LEAST 50-50 but you can increase the amount of plant section to up to double that of the fish section. You need plenty of plant populated biofilter! Details depend on fish species and the fish stocking rate in your fish tanks.
  • Always have enough plants in the system to clean up after the fish.
  • Make sure the aeration for the fish is adequate at all times.
  • Make sure the water is circulating through the system at the right speed. Adequate water flow rate is very important fore everything to work properly.
  • Make sure the fish tanks are shaded. You DO NOT want algae clogging up your tanks.
  • Make sure there is enough light at the right wavelengths and for long enough each day for the plants. You may need to use low energy LED grow lights to supplement daylight or beef up shady conditions.
  • If you are using a simple DW system, make sure your filtration section is adequate.
  • If you are using media beds, make sure the media is at least a foot deep, and that there is enough media bed surface area in proportion to the number and size of tanks you are operating.
  • If you have an outdoors system, make sure there is bird netting fixed over the tanks to keep out predators. Otherwise you will find they eat all the fish in your aquaponic system.
  • Don’t overfeed your fish. Leftover uneaten food will rot and affect water quality.
  • Make sure your fish are fed as much as they will eat in half an hour, three times a day.
  • Make sure the feed for your fish is correct for the species.
  • Test your water for ammonia, nitrate, and nitrite daily. Know what this means and what ammonia and nitrite poisoning are.
  • Test your water pH daily. Know why this is important.
  • Check your plants for bugs and diseases daily. Have biological pest control measures to hand that won’t harm the fish in the system.
  • Keep chelated iron of the soluble variety to hand. If plants start looking pale and yellow, add it to your aquaponic system’s water at the right tiny amounts according to the instructions on the bottle/package.
  • Check your fish regularly for disease. Keep pictures of the various common diseases to hand so you know what to look for. If the water quality is kept good at all times, disease should not show up.
  • Never, never use proprietary fish medicines or antibiotics in your aquaponic system. The antibiotics kill the bacteria which make your aquaponic system work, and some of the fish medicines may kill your plants as well.
  • Never, never use ANY pesticides in your aquaponic system, even if they are labelled ‘organic’.  They WILL kill all your fish. The ‘organic’ pyrethrin types are among the worst for fast fish kills.
  • Keep ample supplies of dechlorinated and dechloramined water in spare tanks at all times for top-ups and emergencies such as 50% system water changes in your aquaponic system due to ammonia level spikes.
  • Keep a tank separate from the rest as an isolation tank. This is for newly arrived fish quarantine and also  sick fish.
  • Clean out your filter section, if you have one, once or twice a week, according to how much nitrate you need for the plants and how much fish poo is being produced. Details depend on fish and plant stocking rates.
  • Make sure to have enough seedlings ready to go in the aquaponic system at all times to replace crop plants harvested.
  • Don’t use seed propagating media that are soil-based or that are not sterile.
  • Don’t use peat based seed propagating media, or media that will come apart in the water flow and clog your pipes. Rockwool growing plugs used for hydroponics are good, if expensive. Or a compressed mixture of coir and vermiculite. DON’T USE SOIL.
  • Make sure your pipework is wide enough in diameter to make it difficult for gunk to clog it.
  • Make sure your pipework is easy to get at for maintenance.
  • Make sure that if you are in an extreme climate, your aquaponic system is in a greenhouse and has adequate heating/cooling arrangements for the fish water and the air inside to be kept at optimum growing temperatures.
  • Make sure you can afford the electricity bill and that there are backup arrangements for power cuts and power outages. Otherwise your fish can die within 30 minutes when the pumps and aerators fail in your aquaponic system.
  • Alternative energy systems such as wind turbines, solar panels, or anaerobic digesters and a long-life battery array for nighttime operation may well be a better solution financially for your aquaponics.
  • Make sure you have mechanical backups such as spare pumps, spare aerators, spare grow lights, spare plugs, spare wiring, spare air stones, spare air line, and spare people to look after your system if you are called away from your aquaponic system.
  • Make sure cats and dogs cannot get at your grow beds and hydroponic raceways, and fish tanks. Cats eat fish!
  • Bird proof your system.
  • Child proof your system.
  • If you have children near your system, make sure the fish tanks are adequately covered.
  • Only use sealed-cell polystyrene for the polystyrene rafts of your floating raft system. Paint the UPPER surfaces with non-toxic white paint to reflect light and heat back up off the surface.
  • If you are in an area that has typhoons or hurricanes, make sure you have ways to secure tarpaulins over your system to protect it, and that it is built above flooding levels. Your fish will escape if the floods flood over their tanks…
  • Make sure your system is sturdily built out of non-corroding, non-rotting materials. You don’t want your fish tanks to fall apart.
  • Make sure no sharp edges are exposed in the finished construction of your aquaponic system.
  • Make sure no live wiring is exposed to water and damp in your aquaponic system. You don’t want a live wire to electrocute your fish, or you!
  • Get your aquaponic system checked by a qualified licensed electrician to make sure it is safe and legal.
  • Get your aquaponic system checked by a qualified licensed plumber to make sure it is safe and legal.
  • Make sure you have ways to kill fish humanely according to the local rules and regulations.
  • If your system is in a greenhouse, make sure it is the correct kind of greenhouse set up for aquaponics specifically.
  • Keep a sharp eye out for algae growing in your system, and have a way to get rid of it (water snails or catfish are good in some systems).
  • Make sure your aquaponic system does not leak.
  • Wash your hands before touching your aquaponic system to keep from transferring disease to it.
  • Smokers may well be carrying tobacco mosaic virus on their hands. Wash them as above.

That’s just the short list.

Any other constructive suggestions welcome.

I have bundled up the site as an ebook that prints out properly, unlike web pages. It’s available here and now with over 30 chapters of ideas, comment and advice about aquaponics for just $10.  [paiddownloads id=”1″]

Mar 19

Environmental Issues, Aquaponics, And Agriculture

The environmental issues surrounding conventional agriculture are well known.  According to http://savetherainforest.org, 60% of rainforest loss is due to landless farmers going in to farm along new roads opened up by loggers in the jungle.  This is because their land has been taken over by large concerns to grow crops for export such as soybeans, and also due to population growth in these areas.

There are other tales of soil destruction due to land overuse, which creates dustbowls, and due to the use of substances such as herbicides containing glyphosate, which destroy soil bacteria and distort soil structure in the long term.  For more about this go to the interviews with Dr. Huber of Purdue University, on http://mercola.fileburst.com/PDF/ExpertInterviewTranscripts/InterviewDonHuber-Part2.pdf, which is a transcript of the second part of an interview with him on mercola.com, the website of the world-famous Doctor Mercola.  Wikipedia also has scary entries about this substance if you look it up.

In between desperate farmers and the chemical assault on our soil and environment, which may well be causing other problems such as the disappearance of the bees, without which many crops will not fruit, conventional agriculture is reaching a state where the law of diminishing returns comes into play.

These environmental issues have spawned a rise in the adoption of organic farming, but the question here is that it is vulnerable to the very diseases and blights that are dealt with by the chemical barrage used by conventional agriculture.  As such, it may well not be able to produce enough food if universally adopted. It also takes up as much if not more space on the soil as conventional agriculture and is just as water-hungry.

The next environmental issues, to do with water use in agriculture, are also key.  Worldwide, we are running out of potable water at an alarming rate.  These environmental issues are caused by the fact that for the most part, water is used only once in conventional agriculture, then discarded.  It is hardly ever recycled since it is used to carry away waste and for cleaning, also for irrigation, which consumes whole rivers and lakes.  Due mostly to irrigation, the River Jordan in Israel no longer flows into the Dead Sea.  Many other bodies of water such as the Aral Sea have all but disappeared. ‘Formerly one of the four largest lakes in the world with an area of 68,000 square kilometres (26,300 sq mi), the Aral Sea has been steadily shrinking since the 1960s after the rivers that fed it were diverted by Soviet irrigation projects. By 2007, it had declined to 10% of its original size’-Wikipedia.

Lake Chad in West Africa is also rapidly disappearing.

The north of China is also rapidly running out of water.   It has already used up most of its fossil water resources, the underground aquifers that cannot be replenished by rain. I enclose a scholarly presentation about this vast problem:

However, in the midst of all this disarray, and a tide of misinformation from vested agricultural interests bent on selling more toxic chemicals and genetically modified organisms, purported to make conventional agriculture more efficient at vast expense, there are other less well known technologies which do not require any of these complexities to work, and once installed, are vastly cheaper and less water-hungry to run.

These technologies are all based on recycling water, instead of using it just once.  Recirculating aquaculture (sustainable fish farming) has spawned an offshoot called aquaponics, where plants are grown hydroponically in the waste water from the fish.  This waste water is cleaned by the plants, which absorb the nitrates dissolved in it and use them for exponentially faster growth than normally seen in conventional agriculture. This deals with several environmental issues at the same time.

These environmental issues can be listed as follows:

  1. Water is constantly recycled, and used again and again by the fish and the plants. Less than 10% of the water used by conventional agriculture normally to grow food is required. Evaporation is controlled by covering most of the water surface with floating rafts that suspend the plants in the fish water, and shading the fish tanks. These can also be provided with lids in some situations.
  2. Water pollution from fish waste released into the environment is eliminated completely. Removed fish waste solids are dewatered and used as organic fertilizer after composting. The water from this process is fertile and can be used for irrigation. Still 90% less water or less than conventional agriculture uses,  is required to keep the aquaponics system going.
  3. Toxic herbicides are unnecessary since there are no weeds to pull.  Only biological non-toxic pest control methods can be used, since all pesticides, even the so-called ‘organic’ pesticides based on the pyrethrum flower, kill all the fish dead fast. The chemical assault normal with conventional agriculture is stopped.
  4. Artificial fertilizers are not necessary or used. The fish water provides ample nitrogenous matter which is turned by naturally occurring bacteria in the aquaponics system, into nitrates that fertilize the plants in the aquaponics system’s hydroponic component.  The expense of buying in artificial fertilizers is avoided, and the pollution of fertilizer over-use, stopped.
  5. The space used is around half what would be necessary to grow food using conventional agriculture.  This means that you can grow up to twice as much food on any given acreage than would be possible using conventional agriculture. This does not even count in the harvests of fish that will be produced.  Due to the efficiency of hydroponic growing methods, plants can be spaced at up to half the spacing normally required in conventional agriculture.  They also grow at up to twice the normal speed for plants grown in soil. So you get up to twice as many plants, twice as quickly.  This is all dependent on the types of crops grown, but lettuce and basil can be managed professionally to grow at these rates, for instance, quite easily.  This has revolutionary implications for land-starved farming communities, especially since no soil is needed, so any flat surface can be used to grow food.  You can even grow food on a flat roof surface, in the city.
  6. Fish can be grown intensively on land with very little ecological footprint. The biofilter is the aquaponic system, so none of the notorious water pollution normal with intensive fish farming on its own is caused. This means that there is a possibility of reducing the pressure on ocean fish populations which is steadily wiping them out at present.  1/8 of an acre of aquaponics can rear 5 metric tons of tilapia fish a year, for instance.
Tropical aquaponics-lettuce crop in 29 days, University of the Virgin Islands, 2010

Tropical aquaponics-lettuce crop in 29 days, University of the Virgin Islands, 2010

In places like South America, West Africa and China, the wholesale adoption of this technology could spare the countries in these places further environmental issues, drought, poverty and desperation. However, there are only a limited number of trained and available independent consultants such as myself who are willing to undertake the consultancies necessary to set up demonstration aquaponics systems.

Call me! - Charlotte Appleton: Offline

» Get Skype, call free! I can be contacted for preliminary discussions via Skype for free.

These aquaponics systems should be set up professionally on a large enough scale to show how aquaponics can replace the methods of conventional agriculture.  Farmers can then be taught how to produce more food using 90% less space and water, and 17% of the energy currently used in conventional agriculture. They will learn that they need far fewer and far less costly inputs to do this than currently used in conventional agriculture.  These inputs mostly consist of fish feed. Aquaponics uses only non-toxic pest control and needs no herbicides.  If you liked this article, I have edited the past 6 months of this website’s posts into an ebook to download on the spot which is available here for only $10: [paiddownloads id=”1″]

To learn more about how aquaponics works, and how to make it work for you, I suggest you read a few of these books from the world’s leading experts on aquaponics and aquaculture:


Feb 24

Feeding Fish Sustainably.

The main input in aquaponics apart from water and energy, is fish feed.  A major component of commercial fish feed is fish meal in many formulations.  Feeding fish sustainably requires that we dispose of this ocean fish component in our fish feed.

Due to ocean acidification and overfishing, ocean fish may disappear in the next couple of decades. So it seems crazy that in our efforts to supply fish through sustainable fish farming, on land, with an eye to taking the pressure off ocean fish stocks, we are creating a market for more ocean fish in the form of ocean fish meal based fish feed.  Our fishing practices should not involve fishing just for animal feed and fish farm feed. We should crack down on those polluters who are destroying the oceans with ocean acidification.

Ocean acidification is happening because of acid rain.  This in turn is caused by our profligate burning of fossil fuels.

Ocean acidification is the name given to the ongoing decrease in the pH and increase in acidity of the Earth’s oceans, caused by the uptake of anthropogenic carbon dioxide (CO2) from the atmosphere.[1] About a quarter of the carbon dioxide in the atmosphere goes into the oceans, where it forms carbonic acid.

As the amount of carbon has risen in the atmosphere there has been a corresponding rise of carbon going into the ocean. Between 1751 and 1994 surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14,[2] representing an increase of almost 30% in “acidity” (H+ ion concentration) in the world’s oceans.[3][4][5]

This ongoing acidification of the oceans poses a threat to the oceans’ food chain.’ From Wikipedia, ‘Ocean acidification.’

In other words, many ocean creatures are going to die because our industrialized society cannot stop polluting the air and water.

Ironically, because fish waste water, used in aquaponics to grow crops, is a miracle grow fertilizer, aquaponics causes plants to grow much faster and at thicker planting densities, which gives aquaponics, if more widely used commercially, the potential to act as a carbon sink.  The rapid plant growth soaks up a lot of carbon dioxide, which is a culprit in the acidification process of the oceans.

There are many other sources of high grade protein that can be used for feeding fish commercially, that do not have to be sourced from the sea and its creatures. Since ocean fish may disappear, we do not need to feed our farmed fish on them into the bargain and further hasten their demise.

Tilapia are omnivorous fish with a marked preference for green leafy vegetables. They do very well on aquatic plants that can actually be grown on the outskirts of a large commercial aquaponic operation, such as duckweed. Duckweed makes them go into a feeding frenzy from my experience. They love it!  It may well be part of the way out of our own feeding frenzy on ocean fish as animal feed.

According to John W. Cross, at http://www.mobot.org/jwcross/duckweed/fish.htm, and other sources such as the permaculture aquaponic farm in Hawaii, Olomana Gardens, duckweed is an ideal food for fish and livestock.  It grows in still and shallow waters and is also useful as a ‘lid’ to limit water evaporation, since it grows very densely in mats on the surface and helps to shade the water from the sun.  In the wild,  duckweed varieties have been used as a food source by fish in all sorts of climates and situations. It is extensively used by aquaponics hobbyists for feeding fish sustainably already.  They are aware of its high nutritional value.

It is a fast-growing  floating plant with few stalks, mostly all leaves. It has a very high protein content, as the above website reports as follows:

‘Much reliable analytic data is available to support the usefulness of the duckweeds as valuable food sources (Landolt and Kandeler, 1987). Most species have protein contents in the range of 15-45%, depending on the nitrogen supply, and the amino acid balance is favorable, with only TRP and MET generally limiting (Landolt and Kandeler, 1987, pp 375-377. The yearly protein yield/ha is up to tenfold higher with Lemna than with soybeans, and nearly as much better than for alfalfa (Said et al. 1979).

Recent work with Lemna paucicostata in Nigeria (Mibagwu, and Adeniji, 1988) indicates an especially high nutritional value. Their analyses of plants from three locations in the Kainji lake area showed a crude protein ranging from 26.3-45.5% of dry weight:

“The amino acid content compared favourably with that of blood, soyabean and cottonseed meals and considerably exceeded that of groundnut meal. The levels of the essential amino acids surpassed the FAO reference pattern, except for methionine which met 61.4% of the recommended value. The levels of minerals were high but should not pose any toxicity problems if incorporated into animal feeds. The levels of nitrogen in the plant are comparable to those in commercial fertilizers. The plant could be a good dietary supplement and nutrient source for humans, livestock and fish….” “With an average standing crop of 309 kg dry mass/ha and doubling time of 1.2 d, 129 kg DM/ha of dry duckweed are obtainable daily in the Kainji Lake area, which could ensure a daily supply of 59 kg of high-quality protein for poultry and fish feed formulation….”‘

Trials reported on the same site had mixed results with feeding diets of duckweed alone to tilapia.  Mixed with conventional feed, however, it showed improvement in fish growth.  More trials need to be done on using duckweed for feeding fish sustainably. Duckweed may also turn out to be very useful in aquaponics systems as a backup plant for sopping up excess levels of nitrates in the water.

However, there are other food sources that can be grown from vegetable waste offcuts composted at the end of the harvest cycle (which happens once a week in most commercial aquaponics systems).  The first of these food sources for feeding fish comes from the soldier fly.  Fish love to eat its larvae, which are very nutritious, and have the incidental advantage of being self-harvesting.  Soldier fly larvae have been used in various trials for feeding fish and livestock with encouraging results, and have been used to replace menhaden fish meal quite successfully.

See Sealey et al 2011troutblacksoldierfly and A2.

A university and a  non-GMO soybean company are developing a sustainable oil product to replace fish oil in fish feeds for trout, salmon, and other farmed fish.  At the moment the EPA oil component in commercial fish feeds is derived almost completely from millions of tonnes of anchovies and sardines caught and fed into the fish oil processing industry’s plants. This is completely unsustainable. It takes tons of these fish to produce mere litres of oil.  What is this doing to ocean ecosystems?

This company promoting sustainable aquaculture is called Imcopa and it is using microseaweeds to research ways of making this new high EPA oil as a component of its sustainable fish feed based on plant sources and not ocean fish.  Ocean fish may disappear if we carry on exploiting them hand over fist as at present.

This microseaweed oil contains the right Omega 3 and 6 fatty acids that farmed fish require to maintain healthy growth.  Trials are in progress to see how this oil can be used when feeding fish sustainably. It will be mixed with soybean products to produce a high fat balanced feed for farmed fish such as trout and salmon. When the research is concluded, the company hopes to market the product worldwide.

Grain amaranth has been tested on carp in an aquaculture situation with encouraging results, and has an advantage that few people realize: it can be grown in part of the aquaponics system as a prolific grain and green vegetable crop, and then fed back to the fish! See the middle parts of Samlet-rapport-amaranth from the EU-supported Mexican and Nicaraguan research on the uses of amaranth grain.

Amaranth grain has a very high nutritional value and is palatable and suitable for feeding fish sustainably.  It is also a very tough crop that grows like spinach either in soil or even, like spinach, in aquaponics systems.

As you can see, there are many possibilities for feeding fish sustainably  without using fish meal, fish oil, and other feed derivatives sourced from ocean fish.

If you have your own experiences with feeding fish sustainably, please do not hesitate to contact me!
If you have a lot of questions about aquaponics, there is a splendid book out by my old teacher, Dr. James Rakocy, which should help you clear up those uncertainties.

Feb 18

Aquaponics, Urban Farming And Sustainable New Cities

With aquaponics, sustainable urban farming reaches new heights of sophistication. As a module in the design of new cities it becomes increasingly attractive when it is realized that with aquaponics, the sustainable new cities would not need to import nearly so much material in order to feed themselves. Aquaponics, properly designed and managed, allows whole residential and commercial building complexes to recycle their organic waste within the building back into clean, safe food.  Very large quantities of food can be grown this way on very small areas.  No soil whatsoever is needed.  The crops grow in fish farm waste water.

Of course there are intermediate organic conversion modules that separate the human waste and food waste from the human food chain for practical and hygienic reasons. Various composting methods can be used to bring human and food waste to very high temperatures for long periods of time.  This eliminates the risk of human pathogens being passed on to the aquaponic urban farm stage of the recycling process.  Sustainable urban farming does not have to be toxic urban farming!  Aquaponic farming should be carefully managed to exclude human pathogens, which can easily contaminate the water if you are careless or inattentive.

Composting can also be used to breed insects as fish food.  The main input for aquaponic farming is fish food, so it is essential to source this from sustainable sources, which are also cheaper than buying in food, when it can be grown actually in the aquaponic farming enterprise itself. Aquaponics is the marriage of intensive aquaculture (fish rearing) and intensive hydroponic vegetable and fruit cultivation, in a recirculating aquaculture process that uses a tiny proportion of the water normally required for agriculture.  It is practical to re-use vegetable offcuts and insect larvae grown in various composting processes for fish feed, so that no fish food has to be bought in from outside.  This also divorces the fish rearing industry in the city from dependence on commercial fish feeds using increasingly scarce and expensive ocean fish as a base.

However, in a new build city design, composting areas tied into the waste disposal system would have to be part of the integrated sustainable city design.

Methane gas is also a desirable and useful by-product of composting that can be compressed from the waste digesters and used for cooking gas, for instance.  It can also be used to run boilers for steam for dynamos to produce electricity for city use.

To go back to the fish feed issue, basically insects such as soldier fly larvae have proven easy to harvest (they can be bred in a waste composting design that takes advantage of their tendency to crawl on their own into the hoppers provided) , and very nutritious and acceptable to fish such as tilapia.

Aquaponic urban farming systems could easily be established all over the flat rooftops of any city design, as long as the load bearing properties of the underlying buildings were beefed up to bear the weight of the water tanks necessary.

Aquaponic urban farms on rooftops could also double as amenities, with their own cafes and restaurants serving fresh food out of the integrated aquaponic systems designed to be aesthetically pleasing as well as efficient mass food production areas.

Flowers and fruit can also be grown aquaponically, and plants such as grain amaranth, for instance, grow excellently in aquaponic systems and provide a high protein grain that requires no further processing after harvest apart from drying, as well as ornamental flowers and edible leafy greens.  An inspired designer could design local rooftop parks which as well as being pleasant to use, were also aquaponic farming areas of ornamental and economic value.  It is simply a matter of siting the fish tanks and aquaponic tanks and the requisite pumps and plumbing imaginatively and ergonomically.  In colder climates, greenhouse structures can be integrated with the building design in the first place to include malls,  leisure areas, and so on into the design.

Banana plants and papaya trees will grow in growing media based aquaponic troughs, as part of a permaculture section of the rooftop or back lot aquaponic farm.

Since you need no soil at all for aquaponics, designs for sustainable new cities based on floating structures could also house aquaponic farm parks for their populations, recycling waste back to food and drawing the little water they need from desalination plants powered by the sun, or by methane driven electric power plants from the recycling of that same organic waste matter.

This technology has the potential to revolutionize how new cities are designed and run in order to be sustainable.

To find out more about how aquaponic farming can be built in to sustainable new cities and to understand this technology better, I highly recommend reading the following aquaponics textbooks to get a more expert viewpoint on aquaponics:

Aquaponics Global Anthology 1 is available for instant download and to print out here: [paiddownloads id=”1″]