Jul 30

Cold Water Fish Species In An Aquaponics System.

Cold water fish species such as trout can be reared in aquaponics systems, but at much lower densities than tilapia in warm water aquaponics.

This is partly because these cold water fish species are less tolerant of the presence of ammonia and nitrates in the water than tilapia, but also because at lower temperatures nitrifying bacteria are less efficient at disposing of ammonia and nitrite.

Like all bacteria, they get their energy from their environment and with less heat in the water, the nitrifying bacteria can only dispose of the ammonia that is being produced by the fish in the aquaponics system at a slower rate than in a warm water aquaponics system.

You still need to protect the cold water aquaponics system from extreme temperatures, so it will still have to be in a greenhouse, since below 10 degrees centigrade the action of nitrifying bacteria is very much suppressed.  Fish such as trout and perch also do not grow well below this temperature.  So you are looking at a temperature range between 10 and twenty degrees centigrade.

This is usually easy to maintain in a normal greenhouse in temperate climates, but in Arctic conditions you will still need some way to heat the greenhouse. Your cold water fish species will not be comfortable if their water freezes solid!

This is where your electricity bill comes in, since you will need to heat the greenhouse so it stays constantly above 10 degrees centigrade, AND ALSO pay what it costs to run the pumps and regenerating air blowers 24/7 to keep your aquaponic fish and vegetables alive and growing at optimum rates.

In Milwaukee, both tilapia and coldwater great lakes yellow perch are raised at Growing Power and Sweetwater Organics aquaponic farms, by the thousands.

The market for sustainably farmed yellow perch, a favourite frying fish for the local population, has increased since pollution in the great lakes caused a massive die-off of the wild version of this species.

Which brings me to the problem of water filtration.

If you have cold water fish species such as trout and perch in your aquaponics system, you MUST make sure you have adequate filtration and solids removal, to keep dissolved ammonia levels to a minimum.

At the Herbs From Wales aquaponic and hydroponic farm in Anglesey, Wales, they have both aquaponic media beds filtering the water, and mechanical sponge filters that remove additional solids.  These are regularly cleaned out to make sure that the water for the cold water fish species (in this case, brown trout) is not stacked full of ammonia and nitrite.

Stocking density (carrying capacity) there for their cold water fish species is much lower than for tilapia, at around 6 kilogrammes of fish to 100 litres of water to 200 litres of grow bed. This is basically the same as that advocated by Backyard Aquaponics in Australia.  In Australia the ubiquitous tilapia fish is banned for fish farming, since it can be invasive if it escapes.  So more nitrate sensitive kinds of fish including Australian native varieties of river perch are used, which are much more susceptible to disease if they are kept in dirty water, with medium to high ammonia levels.  Using the above ratios and either growning media beds or deep water culture (DWC) raceways topped with floating raft growing systems, you can keep your ammonia levels down to the nearly nil levels required to raise these kinds of ammonia levels sensitive cold water fish species.

Make sure you have enough plants growing in the hydroponic part of the aquaponics system to soak up the ammonium nitrate that the nitrifying bacteria are digesting out of the fish waste water! Ammonia levels will soon rise dangerously if you don’t keep the fish and plant stocking levels of your aquaponics system in balance. This applies to cold and warm water aquaponics systems equally.

Making sure that the water is thoroughly aerated at all times both in the fish rearing tanks and the grow beds or DWC raceways is essential as well to provide a buffer against any nitrite or ammonia spikes that may accidentally occur. Excessive ammonia levels will certainly kill your fish. Having high levels of dissolved oxygen in the water at all times helps to prevent this from happening, since nitrifying bacteria need dissolved oxygen in plentiful amounts to digest ammonia efficiently.  Also your fish and plants need to breathe oxygen too!

DON’T OVERFEED YOUR FISH.  Uneaten rotting food in the system will cause major water quality problems and mean you may have to suddenly change out more than half the water in your aquaponics system to save your fish from dying rapidly of brown blood disease, or worse.  This holds for any aquaponics system, cold or warm water.  It’s best to feed your fish little and often, say, three times a day, and only as much as they will eat in half an hour, in a large tankful of fish, that is.  For small hobby tabletop systems, make that as much as they will eat in two minutes.

Finally, remember fish have ears. They can hear. They do not like to be kept in noisy environments any more that you would!

If you like this article, I have edited the first six months of articles on this site as the ‘Aquaponics Global Anthology’ – available here: [paiddownloads id=”1″]

Jul 28

Hunger And Aquaponics.

Hunger stalks the planet. There has just been massive crop failure in the grain and soy belts of North and South America,  due to drought and the failure even of ‘drought resistant’ genetically modified crops.  Climate change is seriously disturbing weather and rain patterns globally. With crop failures increasingly prevalent, hunger edges closer to us all.

Conventional agriculture, organic or GM, depends on rain and rapidly depleting underground water supplies. Fertilizer is essential and made from ever more expensive natural gas and oil feedstocks. These are also finite, will keep going up in price, and will eventually run out.  The cost of all these chemicals is eventually passed on to the consumer.

In many parts of the world, this means that basic staple foods are out of reach of the incomes of many people already. Hunger has become a normal daily experience for many. Food grown conventionally is just becoming too expensive, and conventional agriculture is just too vulnerable to the crazy weather. Food insecurity and downright hunger are now stalking everyone.
How, then, are we going to eat? While debates rage and conventional agriculture goes on with business as usual, failing due to droughts, storms, and new crop-devastating diseases immune to modern controls, hunger is increasing its grip on human populations across the globe. Conventional agriculture is proving totally unsustainable, if not downright unworkable in current climate conditions. Hunger is even making its presence known among the urban poor of so-called rich Western countries. Food prices are rising at a steady 140% year on year globally.  That includes the food prices in your local corner shop.

The answer has already been invented and is catching on.  It is totally sustainable. It does not use soil, pesticides, herbicides, artificial fertilizers, genetically modified crops or fish, or antibiotics. It wastes 90% less water than conventional agriculture, whether organic or chemicated. It does not need expensive, risky genetically modified seeds, organisms, or plants. If more generally adopted by farmers worldwide, it promises to end food insecurity for millions of people.

It is a way to raise fish and vegetables intensively in the same recirculating water.  It marries intensive fish farming and intensive hydroponics and by doing so, gets rid of the endemic problems of both technologies.  The vegetables clean the water for the fish, so there are no uncontrolled effluent discharges to the environment.  The fish fertilize the water for the vegetables, so no artificial fertilizers need be bought. Plants love this and grow up to twice as fast at up to half the spacing.

It’s part of the Blue Revolution of aquaculture-water farming-that is taking the world by storm.  It’s called AQUAPONICS.

Aquaponics farms both the fish and the vegetables sustainably. Aquaponic systems growing fish and vegetables together can be certified organic. Everything grows in tanks in  aquaponics, and water evaporation is stopped by shading the fish tanks and enclosing the water almost completely in the hydroponic raceways, so at least 90% less water wastage occurs than in conventional agriculture. Most water is constantly recycled between the fish and the vegetables.  Only around 1.5% leaves the system every day as a consequence of fish solids flushing and cleaning, and this can be scavenged back by dewatering the solids, and reused for irrigating soil crops such as orchards.

Aquaponics is a proven technology that has been used commercially since the 1970s. It also uses around 17% of the energy used by conventional farming, since no trucks, tractors, and other machinery are necessary. As a modest user of energy, it is also very suitable to be operated using alternative energy sources such as wind power or solar panels. It’s all on the spot and harvesting is easy, especially with floating raft aquaponics systems, where the rafts are lifted onto trestles and harvested at waist height in a few minutes.

Aquaponics is a way to build efficient, highly productive, sustainable, largely organic food factories. It is industrial agriculture gone green. It’s renewable food. And it fits snugly into a climate controlled greenhouse, and reduces water use on the farm by at least 90%.

It’s taking off right across the United States and Australia. Properly designed and managed aquaponics can easily produce far more food, far faster, than any form of conventional agriculture using soil. Aquaponic farming is the farming method of the present now, not just the future.

Jul 23

The New, New Look Aquaponics Global!

Due to some people having legibility issues, I have re-redone the look of the site. Can you possibly comment on how you like it and whether you want it to stay this way or go back to the old blue site?


Charlotte Appleton,

Aquaponics Global Ltd.

Jul 20

Aquaculture-Finding A Supplier For Fish Fingerlings In Aquaponics.

To start an aquaponics system going, once it is built and filled up with dechlorinated chloramine-free water, you need to gradually add some fish.  This means that you have to find a reputable commercial fish fingerling aquaculture supplier in your area, or one  who can supply you live fish fingerlings by post or courier.

Properly packed in the new ‘breather bags’ which allow oxygen and carbon dioxide to pass in the appropriate directions through their walls without letting water molecules out, fish these days can be up to 48 hours in the bags before they begin to suffer, as long as adequate temperature and ventilation is maintained in the fish transportation packaging that surrounds the bags.

You will already have designed your aquaponics system to fit the needs of the species of fish you intend  to raise. Each species of fish will have different aquaculture requirements that have to be addressed. For instance, see my article on raising trout in a temperate climate in aquaponics.

Most people start their aquaponics systems by adding a little straight ammonia, about a dessertspoonful, which can be got from your local pharmacy, or from any store that sells ammonia for cleaning purposes. Make sure this is pure ammonia, without any soaps, detergents, etc.



Then you let the system bubble with air from the air blowers and flow round and round with the pumps for around four weeks, adding a dessertspoonful of ammonia every week, and test it using a testing kit or sensor to see whether the ammonia is being turned into nitrate or not. After a couple of weeks, start adding plants until the nitrate starts disappearing from the tests results for your aquaponics system.

Now you need to gradually add fish, so as not to overload the new system with too much ammonia for the still settling in nitrifying bacteria in it to handle. Don’t overload the aquaculture part of the aquaponics system or you will have a disaster on your hands! Make sure you have enough plants in the hydroponic system part of your aquaponics system to soak up the nitrates in the water that the fish are producing.

Finding reliable fish fingerlings suppliers in your vicinity, county, state or country is usually something you should do at the planning stage of your aquaponics system. It would really be silly to have built and filled up your aquaponics system and then found that it was impossible to supply it with fish fingerlings (baby fish).  However, breeding fish for aquaculture is actually a booming industry and so it is not as hard as you might think to eventually find a good trout breeder or tilapia breeder who can reliably supply you with your fish fingerlings.

Commercial trout farms, for instance, usually also supply trout fingerlings  to trout sport fisheries such as estates with trout streams and trout lakes.  But you will need a guarantee that the trout fingerlings you are buying are healthy and free of disease!  Finding trout for your aquaponics system is not an easy task, it requires painstaking research on your part.  The trout you use should also be made incapable of breeding in the tanks. On a fish farm, breeding should be carried out in a special section under strict biological controls. If you do not want to do this, you have to depend on a reputable supplier of fish fingerlings for aquaculture.

The same applies to suppliers of tilapia fingerlings for aquaculture.  In the case of tilapia fingerlings, you should also make sure they are all guaranteed to be male, or your product at the other end of the cycle will be undersized, it will be impossible to work out feed ratio, and you will have all sorts of different sizes of fish in the pipeline, due to breeding in the tanks.

The best way to check your aquaculture suppliers are reputable is to ring around a few other trout fingerling buyers such as sports trout fisheries and find out who they used or have used in the past, and what results they achieved with the fingerlings they received.

As with any other business, an aquaculture supplier’s reputation is only as good as their product. Your aquaponics system product’s reputation is also founded on the fish fingerlings breeder you choose to use. Whether you are raising trout or tilapia, the quality of your fish fingerlings will to a large extent determine the quality of your adult fish product.  Aquaponics is an intensive fish farm married to an intensive hydroponic farm, and you need top quality fish fingerlings and top quality seeds to make a profit.  This means a reliable aquaculture fish fingerlings supplier is vital.

The rules for getting hold of fish fingerlings for an aquaponics system are really no different from those applying to a straightforward fish farm.

If you liked this necessarily rather general article and would like to have similar or more how-to articles to hand, I have edited the first six months of posts on this website into an over 30 chapter ‘Aquaponics Global Anthology.’ This saves you having to navigate all over this site for information and is printable, since it is a .pdf format file.  This is immediately available from here to download now:

[paiddownloads id=”1″]

Jul 18

Occupy Your Flat Rooftop With Aquaponics.

DVD How To Build Aquaponics. Click here!

Do you have a flat rooftop on your high rise apartment building, community center, high rise car park or school?

Do you have basic construction skills, know how to use a saw and a hammer?

Does your roof have at least 600 kilos per square metre weight loading tolerance? (This is important, water is HEAVY, although not nearly as heavy as wet soil, which contains rocks as well).

OCCUPY YOUR FLAT ROOFTOP WITH AQUAPONICS and start your aquaponic farm up there in the city where the demand for food is.

You can adapt your roof with fish tanks and hydroponic raceways that hold only water and grow far more food than any soil farm can grow on an equivalent limited space.

Do your homework properly and get permission and a community of growers together BEFORE you occupy your flat rooftop. Your flat rooftop is either the property of the person who lives beneath it or the property of the building’s owner.  You don’t want your aquaponic farm thrown off your flat rooftop into the street or a court order forcing you to demolish it. Make sure your flat rooftop is really able to support the total weight of your aquaponics systems before you occupy it.

Once you have got permission, there is a lot of planning and thought that has to go into designing and costing your aquaponics systems before you occupy your flat rooftop. A lot of the information about how aquaponics works and how costing works out is here to download for free:


I have also put together an over 30 chapter collection of posts from this site about many aspects of aquaponics as  ‘Aquaponics Global Anthology 1‘ which you can download instantly to print out from here:

[paiddownloads id=”1″]

DVD How To Build Aquaponics. Click here!

There is also a very good DVD with clear diagrams of how to plumb in the pipework of your rooftop aquaponics system:

Jul 17

Use Aquaponics To Save Water When Growing Food

A good book about the water crisis.

You can use aquaponics to save water by up to 90% when growing food. In these times of global climate change and frequent drought, it is very important for farmers to save water!

First and foremost, food is grown in the hydroponics section of an aquaponics system. It usually consists of vegetables and soft fruit such as tomatoes, melons, squash and cucumbers. In the usual sort of farming, you irrigate them once and then throw away the water. In aquaponics, you save water because this water is sent for cleaning to the plants and re-used, for growing food.

Fish are intensively farmed in the fish rearing tanks of an aquaponics system. However, unlike usual fish farming, you save water because the water used by the fish is cleaned by the plants and re-used, since it is miracle gro for growing food, and is not thrown away.

The fish are the source of the nitrates for the plants, and the plants clean the nitrates out of the water, so it can be recirculated clean back to the fish.  The water goes round and round like that. Growing food all the time at a tremendous rate!

The water is in tanks and hydroponic tanks made out of solid walls and lined with pond liner so they do not leak. You save water because the water you are using does not sink straight into the ground and flow away on the first use. It is used again and again for growing food.

None of the water in an aquaponics system soaks directly into the ground. It is kept and constantly re-used.

The water is also covered over and shaded by a shed over the fish tanks, and floating polystyrene rafts full of plants or at least two inches of growing medium such as expanded clay balls (hydroleca or hydroton brand clay rocks) which prevent the water surface heating up to evaporation temperatures.

Less than 10% of the water volume in the system is lost to the outside daily. Some, however, has to be used in a Deep Water system with floating rafts in it in order to flush out the fish poo from the filter into a settling pond for composting and subsequent dewatering.

Meanwhile, you can get five metric tons of basil and five metric tons of fish a year, just as an example yield (from the University of the Virgin Islands’s data on their commercial aquaponics system), off 0.05 of a hectare of growing space with aquaponics. By using aquaponics you save water, at 90% of the water you would otherwise had to have used to get the above results.

If you would like to download more articles from this site about aquaponics to read at your leisure, I have edited together the first six months’ worth of posts from this site into the ‘Aquaponics Global Anthology 1‘.  It is immediately available for download and printing out here: [paiddownloads id=”1″]

Jul 17

Aquaponics And Water Quality

Water quality is extremely important in aquaponics.  Water quality maintenance is the main chore in aquaponics systems apart from propagation, harvesting and fish care.

Water quality in aquaponics involves careful daily water testing for pH, ammonia, KH, nitrite, nitrate, and oxygen levels, just to name the most basic tests that need to be done. For more details about this, see my articles about oxygen and air pumps and the importance of nitrifying bacteria. This can be done using chemical tests, but it is far quicker and more convenient to invest in hand-held battery-operated water testing sensors which are sold for this purpose, and can be bought directly from this page if immediately needed.

If the quality of your water is not up to standard, immediate action is required.  You cannot expect your fish to remain healthy swimming around in their own waste, and your plants also cannot directly digest the fish waste water, without the intervention of healthy nitrifying bacteria to turn the fish waste products into digested and available nitrate fertilizer.

pH and temperature meter.

The most basic factor is the water pH. This should be maintained using tiny quantities of buffering base materials at a level of 7.0 or neutral at all times. Otherwise things may well start to go badly wrong quite rapidly. Adequate levels of water oxygenation are also vital. You should also know the amount of dissolved solids in your water.

Overfeeding your fish can also badly damage water quality because of uneaten fish food rotting in the tanks. You should carefully calculate fish feeding rates to make sure that just enough feed is being given to make the fish put on weight, without damaging water quality, or also starving your plants in the hydroponic part of your aquaponics system. Aquaponics is an ecology!

Total dissolved solids meter.

Water quality maintenance requires at least a high school level understanding of biology and chemistry. Aquaponics is agricultural science, and as such requires a basic level of education and training in at least the main responsible staff on the aquaponics system.


However, using color coding, which is a common way to design chemical testing materials, even illiterate staff can eventually be trained to use a color coded water quality testing kit to determine if emergency measures have to be taken.  But this should be only a backup measure, to ensure that someone can look after the aquaponics system in the absence or incapacity of the main aquaponics technicians.

If you liked this article, I have edited the first six months worth of articles on this website into the ‘Aquaponics Global Anthology 1′ in printable .pdf format. This can be downloaded immediately here: [paiddownloads id=”1″]

Jul 16

Water Gardening With Aquaponics.

Aquaponics is growing fish and plants in the same integrated recirculating water aquaponics system.  This is usually used commercially to grow up to twice as much food in up to half the time normally needed in conventional agriculture.  That is up to four times as much food as on the same space used by conventional agriculture.

Also, a lot of edible fish are needed to be farmed in the system, as well as the crops, in order to nourish the plants.

koi carp

Koi carp.

But you can also grow a lot of ORNAMENTALfish, such as koi carp, quite intensively in your aquaponics system.  Not as intensively as tilapia, which are more robust, but at quite a high fish stocking ratio, as long as you have enough plants growing in your system to eat up the nitrates produced in the filtration media. Some varieties of tilapia and trout are also very pretty to look at. Blue Australian marron crayfish are fascinating and bright blue! Water gardening is also for the aquarist. Gardening here also means looking after commercially farmed fish if you like.

water garden

water garden

You can of course grow ornamental plants in an aquaponics system. But did you know that there are a lot of vegetable plants that are also ornamental and that grow fast in an aquaponics system? They make water gardening with aquaponics very easy.

Okra, for instance, is a form of hibiscus.  It has a spectacular flower. It goes crazy in a floating raft aquaponics system.

okra flower

Flowering okra

There are lots of varieties of green vegetables which are also ornamental, such as fancy lettuces which come in all sorts of colours from green through to purple and almost black, and with different forms of frilly leaf shapes. Artichokes, if left to flower, are a giant thistle.

Lots of culinary herbs such as basil also come in different leaf colours and/or have attractive flowers. They also have fascinating scents.

And a lot of other plants which are not generally eaten such as marigolds and many varieties of plants used for cut flowers will also grow in an aquaponic system.

By constructing hydroponic beds to resemble the many different levels of a flowing stream, with waterfalls which also help to maintain water aeration, you can put together a very attractive aquaponic water garden with recirculating water going back to the ornamental tanks full of fish.

This recycling of the water with your water gardening means you will safely only use around 10% or less of the water used by conventional gardeners, as long as the tanks remain mostly covered with floating rafts or floating vegetation. You can even water garden in a hose ban or drought with aquaponics!

lettuce colors

Some colors of lettuce

If you liked this article, I have collected similar articles about aquaponics in the more than 30 chapters of ‘Aquaponics Global Anthology 1′ printable ebook, available for download here: [paiddownloads id=”1″]

Jul 16

Drought, The Polar Ice Caps, And Aquaponics.

lettuce seedlings in the UVI aquaponics system

Lettuce seedlings in the UVI aquaponics floating raft system. 29 days from seedling to market size.

All over the world, weather patterns are being affected by record melting of the polar ice caps this summer.  This is causing drought in the United States and South America, while record rainfall in places like the UK is causing serious flooding. This is because the icy water released is altering the course of the Gulf Stream and other ocean currents that drive the weather globally.

Meanwhile, farmers are suffering from crops being lost due to this melting of the polar ice caps.  This means the price of food will go up sharply worldwide by next year or earlier without a doubt, as food supplies from last year are exhausted and not replaced from harvests that failed this year.

In conventional farming, it takes a whole season in most cases, 180 days at least, to replace a crop that has failed, and if the crop is grown in a place with a harsh winter climate, it will take a year for that crop to be replaced. So in many parts of the mid-western United States, for instance, where the winters include snow and ice, the grain crop that is currently failing will not be replaced for a year.

In aquaponics, a water-saving farming method using a mechanical aquaponics system (see image, left) which requires less than 10% of the water used by conventional farming methods, crops grow up to twice as fast at up to half the plant spacing in the rows.  This means that if a crop fails for any reason, up to twice as much food as grown in conventional farming can be grown in up to half the time. Leafy green spin

Also, droughts cannot affect an aquaponics system very badly, since it constantly recycles the water it uses, and only loses less than 10% of the water used a day to the outside, where this water is reharvested and can be used for normal soil crop irrigation.  Crops in an aquaponics system are grown in this recycled water from intensive fish farming, and the water is then returned clean to the fish to be re-used again and again.  A well designed aquaponics system actually loses only around 1.5% of the water in the system daily to the outside for re-use elsewhere.

Conventional farming loses 90% or more of water used daily to the environment.  This is why it is so vulnerable to drought. This is the same using a drip irrigation system or overhead irrigation. The water used in a drip irrigation system is only used once.  It is not recycled for re-use over and over again. Although a drip irrigation system is a good way to save water during a drought, it is not nearly as drought-proof as an aquaponic system, which, although it grows crops in a large volume of water, is specifically designed not to lose any significant amount of that water to the environment through evaporation and venting to the outside. A great many different crops including corn and pseudograins such as amaranth and quinoa can be grown very successfully in a properly managed and designed aquaponics system.  Amaranth is related to ‘Chinese spinach,’ a stir-fry vegetable.  Both the leaves and the seed heads, which require little further processing, can be eaten.

With this year on year continued massive meltdown of the polar ice caps and subsequent disturbance of weather patterns, drought and flood conditions look set to continue.  This does not bode well for the world’s food supply and all farmers need to save water and be in better control of water use generally. Also where floods are concerned they should be able to protect their crops from those, too.

With aquaponics, they do not just get crops but also useful protein, in the form of sustainably farmed fish.

By growing a much larger proportion of our food in aquaponics system tanks along with fish, which supply the nutrients for the plants free of charge, crops can be grown in controlled off-the-ground aquaponics systems. Aquaponics systems are intensive fish farms tied into intensive hydroponics systems, where the fish waste water is pumped around hydroponics systems and then back to the fish rearing tanks. No expensive fertilizers are needed. The fish make the fertilizer. It’s organic!

A short on-site training session is all that is required to turn a conventional farmer into a skilled aquaponics system farmer. Such a farmer is prepared to farm without being anything like so vulnerable financially to the weather in the form of drought and flooding.  If the funds are available, an aquaponics system can even be built inside a climate-controlled greenhouse!

Jul 14

Arduino-Based Aquaponics In a Food Desert.


This is food being grown in an aquaponics system in the middle of a concrete food desert in Oakland, California, USA.  Food and fish are growing well due to a lot of dedication and attention.

This is a clear explanation of a small aquaponics system that is almost completely automated and off-the-grid. It uses solar power. This aquaponics system talks to the farmer on his mobile phone, telling him what is going on with his fish and if his food is growing well.

However, if any of the automated sensors break, for any reason, disaster could happen to an aquaponics system, with no-one actually there to fix it.  A lot of aquaponic systems have a 30-minute time margin before massive fish deaths begin due to aeration and pumping not happening or being substantially reduced. This will happen even in an automated system. This means that if you get stuck in a traffic jam trying to get to your automated aquaponics system to fix the pump, many if not all of your fish could be dead by the time you get there. Automated systems for aquaponics are certainly attractive, but you have to realize they also have automated limitations!

If the sensors are out of action, you may arrive the next day to find a lot of dead fish and your plants wilting.

Growing media based aquaponics systems like the one in the video do not retain water in the growing media.  Inert growing media such as pea gravel and expanded clay balls, also called “clay rocks”, “hydroton”, and “hydroleca”, do not retain or store water like earth and compost do.  If the pump is out of action, in a flood and drain system, or even some constant flow systems without standpipes in the growing media filled growing beds, all the water will return to the fish tanks. Then the growing media will rapidly start to dry out.  If this is happening in hot weather, you had better get there extremely quickly!

If you like this article, the aquaponics article-packed Aquaponics Global Anthology 1 is now available to download here:

[paiddownloads id=”1″]