Lost my love for aquaponics

First a little bit of background:

Before I learned of Permaculture, I was in love with the idea of aquaponics.

I really thought it was going to be a new career for me. With demand for seafood growing, and wild supplies crashing, a huge market for sustainably farmed fish is forming. I liked the idea of using a recirculating aquaculture system and thereby being safe from the pollution affecting wild fish. I liked the idea that my system would be water efficient and produce multiple products. I was going to save the world AND make a living while expanding on my enjoyment as a hobby fish keeper.

For three years I lived with the idea that I was going to become an aquaponic farmer. I studied everything I could get my hands on, and worked on designing a farm. I joined the Wisconsin aquaculture association and went to their conference on recirculating aquaculture systems. I even convinced my wife that touring the aquaculture demonstration facility run by UW Stevens Point counted as a vacation.

During this time, I constructed three hobby sized systems. Each time I learned so much in the process that I had to start over and design a new setup. It sure felt like progress at the time.



Then I had some revelations that stopped me cold.

1. I don't know jack about growing vegetables.

We always had a vegetable garden growing up. I eat vegetables. Surely I must know what I am doing right? Well intensely observing the plants growing in my system made me realize just how much I didn't know about them, and without understanding how plants grow in soil, how could I guage the success of my system?

2. My systems required massive amounts of energy and some questionable materials.

One of the first things I realized was how fragile the systems were and that even a short term power loss could wipe out my livestock. I was heavily dependant on plastics for numerous components (pumps, piping, liners, net pots...) which led to a lot of wondering about the embodied energy and potential contaminants attached to those parts. Even a tiny toxin can build up in a closed loop system. After wandering lost in a sea of materials science that towered way over my head, I took my unanswered questions and quietly left. This is a job for someone with way more resources than I have to offer.

3. Fish food is made from fish protien which is made from ...well... FISH.

This was the deal breaker. In my head I was building a system outside of nature and not subject to her woes. Now I know that such a system does not exist on this earth. My concept of fish farming without impacting wild populations or taking part in the pollution stream was always just a pipe dream. It does not matter if you remove a one pound fish to eat, or 1 pound of tiny fish to grind up into fish meal and feed to the fish you plan to eat; the impact on the waterway is the same, and the accumulation of mercury, PCB's, pthalates and other fun stuff is the same as well.

I believe there is potential to farm insects as a sustainable protien source, but I have neither the resources or inclination to figure that one out. Until someone does, fish farming will not be sustainable in any form.

So thats it, a quick overview of how I fell in then out of love with aquaponics. I hope you can take something from my experience and I'd love to hear how others feel about these issues.

I just wanted to add that I do not regret the experience at all. I learned a lot and many of the concepts, like understanding the nitrogen cycle for example, have truly enhanced my understanding of soil. Still, I have learned many new things since then and now I can't imagine growing plants in anything but a healthy, living soil with intact fungal networks. These days the only thing close to aquaponics that make sense to me are Mollison's drawings of trees hanging over waterways, feeding and shading fish in a natural setting.

I really appreciate your candid summary of your AP experience.

AP is often touted with alot of really far out claims, production times and numbers, "closed loop", anyone can do it... etc., etc.
Just like anything any other method of farming and gardening it requires work, knowledge, skill and energy/materials. I am always amazed that people sell the idea of AP and that others believe; that they can grow food, fish, build a system and manage it all in a high state of productivity without any prior experience. I feel that the responsibility lies with both parties being truthful... It is very possible for someone to learn to grow veggies in AP, not that hard really. But you do lack the connection to soil and the huge reservoir of nutrients, minerals, pH buffering, etc. that really make a big difference when you are just starting out.

I feel that it is possible to design and build systems that avoid the excessive energy and questionable materials. A well designed system has an ability to buffer the short term power losses. Linking these to renewable energy sources and batteries provides power for your system and many of the other systems in the home and farm that also require constant power. Energy efficiency of systems design and components are key. Materials sourcing is truly a place for development of AP as we know it. Many options exist that are toxin free, system design plays a key role here too in reducing the excessive materials needs. A thorough energy audit is needed to really get a true sense of the productivity of these systems over their lifetime. I think that including factors such as nutrient density and cleanliness of food (ie Beyond Organic) would be prudent.

Your comments on fish food are spot on. It is crazy that fish feeds derived from wild population stocks, full of GMO's and who know what else... are put into these systems and claimed to be "sustainable, organic, closed-loop," etc. Super crazy to me. Building a system outside of nature and her diversity is not sustainable. Designing systems that link to and speed up nature and her process' moves beyond sustainability and can become regenerative. Fish can be fed many others ways and the "pollution" of this fish farming is one the best ways to jump start natural biological process' which can be designed to yield short term abundance for us and long term stability in the environment. I recently consulted and worked on a large scale commercial AP project that I feel was had an unrecognized effect of remediating pollution of the local watershed. This system used many tens of thousands of gallons of water, all of it could be considered to have high, very high, levels of nitrate pollution. By partnering with beneficial bacteria in a designed system we were effectively removing that pollution by growing foods. A nice little additional yield. This is also one of the areas where I often see crazy claims and numbers thrown around. 10%, 2% percent of the water needed, etc. ?? I would really like to see some hard numbers to back those up. Until then take it with a grain of salt... The system I mentioned used a huge number of gallons in its start-up phase but required a very small fraction of the water to keep it at efficiency. I cannot give hard numbers here as my time on the project was short and I know it was not/is not being tracked. with that said, I know that all of the local farms which border this one on all sides for many miles used an equal amount or more gallons for a yield that was much less per sq. ft. on a daily basis. Not a one-time fill up and then small additions.

Building these systems in warehouses, in cold environments using lights, heaters, etc. is not sustainable. Using your example and linking these systems to natural environments and process' is going to be the way forward for AP. Utilizing these systems in urban environments with toxic/non-existent soils is in my opinion a great fit. Designing a system to run of the "pollution/resources" of these environments is a worthy goal. Until then we will have the growing pains of a developing system methodology.

Great topic you started Josef,
Cheers

When I first learned of aquaponics, it was obvious from the start that it would make the most sense to raise vegetarian fish and those who could live off the waste stream. I didn't give the idea of store bought feed even five minutes of consideration.

I've decided that a naturalized pond situation, using fish that can survive without supplemental aeration or heating will best suit my needs. Production can be enhanced through feeding of farm waste and through regular nutrient removal. I will accept whatever production level proves achievable with the amount of time I'm willing to devote. I'm looking at the aquatic system primarily as a water and nutrient store for the surrounding garden. Fish and aquatic plants will be a nice addition to the garden's production.

I'm 100% sure that if I were to devise a system that is reliant on many systems having to work continuously, that it or I would fail at some point. It's absolutely essential for me, that the whole system can operate during my absence. This could be a day or a month. Even the most ardent proponents of bells and whistles will agree that only a fairly naturalized system is likely to survive this sort of management plan.

It could be argued that this is not aquaponics. To me, any fish production system that utilizes nutrient rich water from fish habitat to nourish plants, where some of the water is cleaned up and returned to the fish, is aquaponics.

Dale, that is precisely what we are doing as well. I have stocked our irrigation pond for the blueberry farm with various fish, when we irrigate we are fertilizing the plants, the plants attract unwanted insect pests and through the use of bug zappers we are able to feed the fish. Since we run the zappers at night, we do not impact the beneficial bee populations. So far it has worked out well for us. I do have to feed during the coldest months, although I could skip the feeding and just accept the losses that will happen.

Nice to see other folks have come to the same conclusion as us

Living in Hawaii I don't have to deal with freezing temperatures, although even temperatures here can be challenging for aquaculture depending upon the location.

I've just recently embarked on my first aquaculture experiment. For about 6 months now I've kept tilapia in an artificial pond (repurposed catchment tank). While waiting for the pond to come to a natural balance. I've been growing water hyacinth and azola in with the fish. These are harvested and fed to the chickens.

I don't buy fish food. The fish are fed finely chopped kale, worms, plus whatever guppies they manage to catch that hide among the plants. They also have been eating the azola. The guppies are there to eat the mosquito larvae. I'm getting ready now to start growing lettuce in floating cages in order to protect it from the fish.

This is a very low input system. No commercial products. No electricity. I am eager to see if the fish and lettuce grow well enough.

Josef, you have a potential resource in Growing Power, over in Milwaukee. There they are growing tilapia in tanks in hoop house style greenhouses under lettuces. They use compost to warm the greenhouses, and utilize local waste products, like brewer's mash, for their compost. Will Allen has got a good system going there. You could probably go and tour it.

Julia Winter wrote:Josef, you have a potential resource in Growing Power, over in Milwaukee. There they are growing tilapia in tanks in hoop house style greenhouses under lettuces. They use compost to warm the greenhouses, and utilize local waste products, like brewer's mash, for their compost. Will Allen has got a good system going there. You could probably go and tour it.

I wrote a long winded piece about Will Allen a couple years ago. Will Allen-Urban Farmer-Aquaculture Researcher etc...

https://permies.com/t/11316/permaculture/Allen-Urban-Farmer-Aquaculture-Researcher

Thank you for all the great replies. I am a big fan of the work Will Allen does, I read everything I see with his name attached. I am embarressed to say I have not yet made time to go see growing power's operations in Milwaukee or Chicago even though I am right between them.

Dale and M. Foti, I think you are on the right track. Finding ways to connect the inputs and outputs of an earthen pond to other growing systems makes a lot of sense and can greatly enhance both systems. My issue is with recirculating systems in tanks that depend on pumps, filters and heaters to maintain water quality. I think that the even the large commercial systems that make economic sense today are only viable because of artificially cheap energy and plastics. I no longer see this as a path to feed the future.

In many ways, I guess my change in attitude towards aquaponics reflects a change in my attitude towards farming in general. That is; away from large energy intensive monocultures toward smaller management intensive polycultures.

I think of Sepp Holzer's fish production, or of the increadible fish farm in Southern Spain that chef Dan Barber describes in one of his TED talks and the idea of feeding fish bags of processed food seems so bizaar and pointless.

At this time I feel that the only reasonable place for small recirculating systems is in education. They can be a great tool in helping people understand the interactions of fish, plant, and bacteria. Having that knowlege can help us better manage the edge where water meets field and orchard in the real world.

Great topic! I was not aware that fish food was used as a food source that is stupid other than as last resort back up. I always thought that fish farming was carbon neutral, and once set up closed loop buy nature, but obviously that is only true in rare cases. So how does nature pump water up hill? Can we copy that kind of heat differential pump use the sun to supper heat water on the roof from a cold water source at ground level or just below, to creat a heat differential pump . Maybe stack functions with solar panels being cooled by water pumped from the heat differential. Put the Aquculture In between. Add other live stock like chickens over the fish which can be fed scraps and other restaurant waste. I guess the point is not that Aquponics is not worth it jor a hox which is what i kind of got from your post.like many things fads often are made to look easy buy people having done it for along time. Just by them doing it alot. That is the great thing about forums like this which is that I don't have to make the mistake you made or someone else's mistake when including fish to the urban farm model. Don't loose hope just restructure you idea of saving the world, I know that's only a part of the issue. But thanks for the info and the post.
Mikael69

I started in a similar way - mainly as a thought experiment. And came to a similar conclusion.

Although I didn't stop there. I found a thread about fishless systems and started my thought experiments again. I now have a system that uses a local, terrestrial, waste stream for nutrients and 40W, continuous, of electricity (which costs $8 per month where I come from). I am now looking at the idea of stopping the pump overnight to cut that down. The only thing slowing me is the fact that my night electricity costs about 30% of my daytime power, so my savings won't be much to worry about.

I use deep water culture beds to grow lettuce and herbs. This, for me, is the easiest way to grow these kinds of annual vegetables. I am investigating just how many types, that I eat, I can grow. Planned right I figure that each 2m2 DWC bed will cost me another 5W of electricity ($1/month). Each flood and drain bed should come free (the 5W is for air).

The rest of my plan is to convert my annual beds to perennial beds. And that is the piece of the puzzle that makes permaculture, for me, a thing. Annual vegetable beds are in a continual state of pioneering. As unnatural as aquaponics. Now I can let it go and do some serious design with the space - using annuals to pioneer the system, ironically.

Still uses plastic though.

Bill Mollison defines a sustainable system as one that creates (or saves) as much energy in its lifetime as it took to make and run it. Using $ as a proxy for embodied and continuous energy (not necessarily accurate), I think my system is probably sustainable.

Here is the Dan Barber TED Talk I mentioned earlier. If you have not seen it, give it a chance. This is permaculture in fish farming.

When I first heard about aquaponics it seemed to be fascinating because you can raise fish in a tiny garden. However when I heard pumps and plumbing the fascination was over. I don't understand electricity and hate everything with pipes.
1.) Why shouldn't I use the soil I have rather than putting plastic barrels on the top of it?
2.) aquaponic vegetables are surely inferior because they grow soil less and I'm pretty sure you cannot grow everything.
3.) I guess it costs far more than what you harvest for at least ten years.
If you look at the pictures there are always a lot of lettuces and silverbeet, exactly the veggies a most brown fingered gardener cold grow.
But it seems that a few people run successful small businesses selling the systems (but not selling the produce!).
I still find the fish side interesting and it would be great to be able to raise fish in the backyard.

1. You make a good point about the soil Angelika, although it is quite clear that not everyone has access to soil. Or good soil. Urban environments for example.

2. Most lettuces on sale in supermarkets now are hydroponically grown. It appears to be very economical to do so, and hydroponics lends itself to automation. Aquaponics is kind of like organic hydroponics, which has the added advantage of no water changes. While I am not qualified to comment on the quality, my lettuces taste pretty good which is a good sign for me. Granted, I have not compared the same variety of lettuce grown in water and in soil for taste. A New Zealand company is comparing hydroponics with aquaponics: http://www.berrysmith.org/projects/aquaponics-vs-hydroponics.

3. You could well be correct on the payback time. Although I imagine it depends on scale. No one would invest in hydroponics if the return wasn't worth it. In my case a single lettuce per week (at the cheapest price I can buy it) pays for the electricity, and another lettuce pays for the capital cost. And if I were to rebuild my system I could probably do it for 50% (just what I learned in the process).

4. I have seen photos of a lot of things grown aquaponically. But you are probably right - you cannot grow everything. But you don't need to. If I could pick all of my salad ingredients (except maybe the caesar salad dressing) from my system I would be very happy.

5. The idea of growing fish entices a lot of people. And this probably accounts for the small businesses selling systems. But think about it for a moment. If you were growing fish you would need to get rid of the nutrients. Some people do water changes. Some people grow water lilies. Some people let algae grow. Really smart people create a wetland to soak up the nutrients and recycle the water back into the system. Really, really smart people construct a wetland of lettuces.

Having said all of this, the other posts in this thread make a really good point about the sustainability of using sea-sourced protein to power these systems. It has been noted, by more than one commentator, that the value of these systems are in their vegetable output, not their fish output. So, valuable sea-sourced protein is being converted into the lowest of all uses - growing lettuce. This, in my opinion, is not a good thing.

Some pioneers have experimented with other sources of organic plant nutrient with good success. So it is no longer aquaponics. A common term they use is bio-ponics.

But still, when the electricity stops, so does your food.

If you grow fish you could water the garden with the fishy water.
If you grow lettuce commercially or for yourself that is an entire different thing. I only sow rows and thin while eating.
But it is true that aquaponics is great were the soil is full of chemicals and can't be used.
For aquaponics you must maybe be more of a builder type of person than a gardener.
Still I find the fishy part great.

Many years ago, probably 1986, I volunteered one summer at the New Alchemy Institute on Cape Cod. I was given the task of restoring the aquaponic tanks, which had been unmaintained for a while. It was a fairly low tech system, using a little electricity but no pipes except garden hoses. It was appealing and I've kept it in the back of my mind as something I'd like to set up again someday.

They were tanks about 3 or 4 feet in dia, about 5 feet tall, made of a fiberglass called kalwall. They were homemade tanks, by making a rectangle into a cylinder and attaching it to a circle on the floor.

They stood in a solar greenhouse as the major thermal mass for heat storage, and also provided rich water for the plants, and nourished fish, and one or two of the tanks had a screened layer on top growing some hydroponic leafy greens.

There was one tank without fish standing on the highest level of the greenhouse. We would let tap water into that tank and leave it there to warm up and offgass its chlorine. These days water may be treated with a form of chlorine that doesn't offgas, so that might be a new issue but back then chlorine did offgas just fine. You don't want to change the temperature for the fish too suddenly so that was the other reason for this tank. So you'd drain some dirty water from the fish tanks into the gardens, and put this clean warmed water into the fish tanks. Not too much on any given day, just a portion of it.

The tanks with fish were so dark green with algae because of the sun coming through the fiberglass, that they were almost black, but actually they weren't supposed to stay that dark. There were three species of fish, as I recall -- the tilapia eat the algae from the walls of the tank, the catfish eat the scraps that fall to the bottom, and I'm not sure I remember what the other species was. Maybe carp?

The idea was for it to be a nice permaculturey kind of system. We would throw weeds into the tanks for the fish to eat, and we'd water the garden beds with the tank water. I don't remember other fish food being put in, though I could be forgetting.

There was an aquarium bubbler hanging down to the bottom of each tank, and a filter consisting of a nylon stocking foot that would fill up with dark green fish shit kind of stuff that was obviously just great for the plants or the compost heap.

I cooked a dozen tilapia one day for everyone's lunch, but it turned out that many of the tanks no longer had any sign of the fish anymore, once I'd changed the water gradually and tried to lower the level and catch the fish. Nobody had been maintaining the tanks or trying to harvest the fish for many months before that.

It seemed like if you kept it at a low stocking rate it might be a sustainable system. I liked it.

Without getting into the rest of the issues, let me tackle the fish feed as I believe that the argument about using wild fish stock to feed aquaponic fish is a bit outdated. There are at least a couple of resources available now that sell USDA organic fish feed which is certified to have no fish meal or soy.

The rub is the cost, which at around $3/lb is at least double the conventional feed.

Please see: http://www.theaquaponicstore.com/AquaOrganic-Organic-Fish-Food-s/126.htm
And: http://premiumfishfood.com/ultimate-organic-fish-food.html

From the latter (and no, I don't necessarily know what I am looking at, so if someone with more knowledge can point out other "gotchas" please pile in)

GUARANTEED ANALYSIS
Crude Protein (min) 32.000%
Crude Fat (min) 4.680%
Crude Fiber (max) 8.700%
Lysine (min) 1.700%
Calcium (min) 0.700%
Calcium (max) 1.200%
Phosphorus (min) 0.400%

Ingredients: Organic Wheat Middlings, Organic Rice Bran, Organic Canola Meal, Organic Corn, Organic Linseed Meal, Dicalcium Phosphate, Lactobacillus Acidophilus Fermentation Product, Reed Sedge Peat, Monosodium Phosphate, Magnesium Oxide, Sodium Sulfate, Manganous Oxide, Folic Acid, Niacin, Choline Chloride, Biotin, Riboflavin, Vitamin A Acetate, Vitamin B12, Vitamin D3, Vitamin E, Calcium Pantothenate, Ethylenediamine Dihydriodide, Beta Carotene, Pyridoxine Hydrochloride, Ascorbic Acid, Yeast Culture, Thiamine Mononitrate, Ferric Choline Citrate Complex, Organic Dried Kelp, Zinc Amino Acid Complex, Cobalt Choline Citrate Complex, Salt, Copper Choline Citrate Complex, Manganese Amino Acid Complex, Potassium Chloride, Attapulgite Clay, Organic Fenugreek, Organic Grape Seed Extract, Organic Lecithin, Enzyme Product, Organic Aloe Vera Juice, Calcium Carbonate, Sodium Selenite, Citric Acid, Calcium Hydroxide, Copper Sulfate Pentahydrate, Zinc Sulfate Monohydrate, Manganese Sulfate, Organic Garlic, Diatomaceous Earth, Silicon Dioxide, Organic Dried Whole Milk, Organic Sugar, Potassium Citrate, Calcium Sulfate, Magnesium Sulfate, Activa Natural Source Mg, Fe, K, Organic Potato Starch, Organic Dry Whole Egg, Organic Tomato Powder, Organic Sources of (Orange Peel Powder, Cayenne Pepper, Dandelion Root, Dandelion, Cloves, Sage, Peppermint, Fennel, Hops, Parsley, Thyme, Lemon Grass, Elder Flowers, Chamomile Flowers, Licorice, Basil, and Ginger), Fumaric Acid, Organic Oat Groats, Yucca Schidigera Whole Plant Product, Organic Water Extracts, Organic Gelatin, Iron Polysaccharide, Copper Polysaccharide, Magnesium Polysaccharide, Manganese Polysaccharide, Zinc Polysaccharide, Zinc Sulfate, Pectin, Granite Dust, Perfect Food Berry, Ferrous Sulfate, Zinc Oxide, Sulfur, Organic Rice Protein, Copper Sulfate, Yeast, Cobalt Carbonate.

My contributions here all go in the same direction: isn't there aquaponic without the plants?
While in certain situations it makes perfectly sense to grow your plants aquaponically, most have
a garden with soil. And most people like playing in the soil and my uninformed guess is that soil
veggies have more minerals too. But growing fish in the backyard, that is tricky, at least I have never seen it.

At New Alchemy, most of the tanks did not have hydroponic vegetables on them. We just used the dirty fish water for the soil in the gardens and threw weeds and vegetable scraps in the tanks for the fish. No, you don't have to have hydroponic vegetables on top of the tanks. But whenever you keep animals (such as mammals, birds or fish) you should have garden soil to use up and recycle the nutrients from their manure.

I have been geeking on this topic latelynand my reading suggests aquaponics work great with wicking beds, and work best when the water is not recycled.
Furthermore the fishtanks are really for making plant food out of waste mor e than making fish to eat.
I have decided to have a pond growing
Koi and duck weed that my irrigation water will pass through on its way to my raised beds.
I plan on no feed beyond occasionally letting the koi get to the duckweed.
When the koi get big I will try to sell them, meanwhile we enjoy them.
I hope to use no pumps, just gravity fed rain water.
An aeration may be needed, if so I will choose a solar powered fountain.

Many people feed rabbit or sheep poo to the fish but that would have to be for home eating only due to over-regulation. Pretty sure they feed manure to the fish in some Asian countries.

Actually, page 469 of the PDM has a drawing of devices to bring manure to ponds.

No it is not manure it is humanure.

It's possible that some countries use humanure but certainly not to the exclusion of other manures.

Exploring the aquaculture section of the PDM further, 13.6 is a section labeld FARMING INVERTEBRATES FOR FISH FOOD and there several ways and species listed such as:
cockroaches, mealworms, and sowbugs;
termites;
plague locusts;
pasture grubs;
snails;
zooplankton;
larval flies;
aquatic molluses;
worms.

I know many people set up black soldier fly (BSF) larva systems to feed their AP set-ups so there are plenty of ways to raise fish in AP system without purchasing food.

Hi Josef,

If you're ever in Madison I'd love to chat permaculture and aquaponics. I have an annual, permaculture, and an aquaponic garden together on my lot.

The woman who's editing Aquaponics Survival Communities wrote an expose' on fish food. There's also some research going on with more plant-based food.

I don't think modern aquaponics can function with zero electricity unless you're willing to haul water buckets all day or reduce you fish stocking to really low levels like the ancient Amazonians or the Chinese have in their farms. But with a little electricity you can do a lot. The main ways of minimizing electricity are with insulation, thermal mass, and air sealing to avoid heat loss and evaporation. In my system, I spend about $150 in heat per year in electricity. Much of that could be replaced with wood. I've looked into compost heating and Jean Pain, but the scale is out of my league.

For that $150, I get 50 lbs of trout, 100 lbs of tilapia, and about 200 lbs of basil, lettuce, and spinach a year. That pays for the $3000 dollar system in abut 5 years at the prices I'd pay for those products (I'm cheap). I don't think aquaponics is really commercially viable if you want to be paid a salary, but backyard growing it works great for me.

I also don't think there is much hope of getting away from plastics anytime soon either, although if you use freezers as fish tanks you don't need it in that component. There is also some research about nitrification bacteria neutralizing vinyl chloride but I can't find it at the moment. Here's a comparison of PVC to HDPE.

Hello, even though this is an old topic I don't think the resolution is final or can't the issue be enriched by points and counterpoints.

1  Many have attacked the idea of urban soil but in some cases, in urban non-industrial areas, soil may be way better than what you may find in rural areas where industrial farming has been a constant practice for the majority of the 20th century.  The reason is pesticides and artificial fertilizers, lack of biodiversity .. etc.  In some patches of land inside old cities, (no lawns) some really clean and lively soil can be found.  Places with an abundance of weeds and wildlife growing seem to me very healthy.  There is air and rain polution but so it is hundreds of miles away from urban centers.

2  What is soil?  I am no expert, but the majority of soil is a "mechanical" medium for roots to be based on to hold the plant/tree up.  Whether sand, loamy clay, pebbles, rock, or perlite, what's the difference?  The difference comes with live nutrient cultures between the pieces of the medium.  Bacteria, fungi, mold, worms, and organic material.  Can this large lively system be contained in a 200gal system or a 20acre system?  No way.  

3  Can we approach/simulate the contents of lively healthy soil in an a closed AP system?  I believe we can give it one hell of a try, if we are trapped in concrete hell with a flat roof, and some sunlight.  It is about the only thing we can do.  

4  The feed for my fish is basically dried vegetable flakes and dried grass shrimp.  I also feed them minced pieces of vegies and fruit.  I try different stuff, stay away from what I am told that is bad for them, and except for the inconvenience of having to prepare supper for them, I use what I know is not artificial or toxic.  At some point I may use some of the vegetables I grow to feed them.  I haven't had much luck yet.  They seem as they have been trainned for generations to eat crappy dried food and don't know what to do with leafy fresh vegies.

5  My trick and experiment, as I do not expect to earn money from it or reduce costs of vegetables (it is an expensive hobby as someone says but 10 years seem a bit of an extreme), has been to try to introduce composting processes into the system.  One simple way is compost tea into the overflow/mineralizing tank.  One other is a compost in a cotton bag (a live culture with attempted inoculation of edible mushroom mycelium) half submerged in a shaded overflow tank.  I don't actually hope to get mushrooms growing from it, but it is not negatively affecting anything yet.  I rotate the contents between the garden pile and the bag.  I add fish poop solids back into the pile and try to filter any solids from going into the beds.  I have yet to find a single worm inside the beds.  You may say this is not an actual closed system, but nothing really is.  Air is full of spores and bacteria, so unless you are inside a bottle it is not really closed.  

6  Double up!  Well, maybe I am not doing aquaponics, but aquatics and hydroponics that borrow from each other.  I may merge the systems at some point, but not yet.  I take water from the fish tanks and overflow, and add fresh water, but not give the fish the water from the hydroponic system.  Although my tests seem to make it close to limits for the fish I'd rather keep both happy and violate the closed system principle.  Although I have added some lettuce cups with their roots hanging straight into the fish tank with mediocre growth.  If in need to move the fish as an emergency somewhere, I believe they will survive a few days into the catch/overflow/mineralization tanks.  Instead of a weekly water change, I take that much/7 everyday.

7  My herbs and teas seem to be all alive and reasonable healthy.  Actually the hardest time I've had was with lettuce and some garlic chives as they seem they had grown too much in the pot I got them from and their roots being all tangled up seem to have been injured by separating and transfering them to the AP bed.  The individual plants all have done great.

8  I think a growth system without fungi somewhere in the circle will be a deficient system, whether AP or land.

I have had a similar experience to some of the others that posted in this thread in the past. I found out about AP and was ALL about it (this is before I found out about Permaculture). I did a ton of research, set up a small system, then a larger system. After that I took a class on Commercial Aquaponics with Applied Permaculture (awesome class...very informative with great instructors).

I was convinced that AP was the way to go. Not so much anymore. I have also become a bit disillusioned with AP. I started a business and built a system that was a bit smaller than "commercial." We were having some troubles, but things were going okay. Then it finally hit me that, I believe as with almost anything in life, massive scale is probably not a great way to go. For me, there is a lot of the original benefit that is lost when things scale too large (be it wind farms, growing plants, aquaculture, or anything else). The minimal ecological footprint, lack of monocropping, ease of maintenance, etc. are lost with a huge system (***in general and only in my personal experience***).

I've met some individuals who are doing some awesome things in the world of aquaponics...integrating Permaculture practices, using a very small amount of energy to run very large systems, producing a wide array of plants, and even seen some pictures of zero energy input systems that were built simply with no pipes or other nasty materials in rural areas of other countries (a young kid that built one of the best and simplest systems that I have ever seen pictures of). So I think that it CAN be done in a way that accomplishes the benefits that people always tout when talking of AP. However, for the most part and especially the larger the system....for the average person it is not as great or as simple as it's cracked up to be. One has to know about tending plants AND about aquatic life, the plumbing can be a hassle, the materials can be questionable, it is an everyday maintenance project (feeding fish at the very least), there are still insect issues no matter what others might tell you, there is usually quite a bit of external energy input that needs to be figured out, acquiring water on a consistent basis, plus many more facets. There is so dang much to know. It is definitely more difficult than "set it and forget it," style. Sure, you can build a small system that is easy to maintain, but you will also most likely only be growing a handful of herbs or one to two vegetable plants in it. To be growing enough to feed a family takes a lot of work.

Finally, I also realized that it is mainly annual veg. that is cultivated in the systems. I have seen the trees and other long term plants in systems, but that is the exception rather than the norm. My plan was to start doing more perennial and self seeding annuals in my large system, but I never made it that far. Here is one of the biggest detractors and what was a huge revelation for me...basically most systems are glorified annual veg. monocrop systems. Where is the diversity? It is not usually viable on a large scale, because of difficulty in planning, planting, harvesting, etc.

All that said, I do think that AP does have a place in certain areas and at certain scales. For me, aquaponics is great for small scale, backyard style systems (especially in urban environments) or as zero external energy input systems that are built from natural materials (rural or urban), such as chinampas, a cleverly designed and implemented system built into the ground, or a system built with natural materials. And of course, there is always more to learn and more areas to grow in...who knows what we will come up with as people keep moving this field forward.

Hey Josef,

I hear you man. It's a darn shame that you lost your love for aquaponics. It has been years I know, and though this may be a long shot, but if you do happen to fall in love with it again, I hope you're doing great with it.

I've had my ups and downs, but overall, I absolutely love running my DIY aquaponics system. I've grown tons of great veggies with it.

The biggest problem I faced when I started out was the water getting constantly dirty and really messing up my tank.

Now,  those of you who are running a small aquaponics system and facing a problem with solid waste and murky water, here are some tips that may help.

First off, don’t acquire too many fish. Maybe your water quality is not up to standard because you simply have loads of fish waste, which means you either lack sufficient plants to get rid of these nitrites and nitrates, or you simply have too many fish.

Try to find the right balance. I know it can be tricky but fish grow and produce more waste as they grow. Perhaps keep logs on how many fish occupy a given set of area for future reference.

Second, forget flakes, use fish pellets! Fish flakes make you water regularly dirty. That’s because they tend to float to a spot hidden by roots or vegetation, so those flakes don’t get noticed and they don’t get eaten. They just dissolve into the water.

Furthermore, the fish tend to scatter the flakes all over the place when they eat them. Pellets can keep food wastage to a minimum and help maintain cleaner water.

Also for newbies out there, if you’re concerned about your fish not wanting to eat right away, please keep in mind that you just introduced them into a new habitat, so they might refuse to eat for the first day or two. Allow them to get comfortable in their new environment first. The only way I can tell if my fish is hungry is to try to feed them. If the fish rejects the food, attempt again later or the following day.

And for those who are completely clueless on building an aquaponics system, yet keen on setting one up, go check this site out.