Farm Research: Aquaponics, the next frontier in sustainable agriculture

          For decades, select academics have been increasingly dubbed human beings as the cancer of the earth (Hern, 1993). In a 2013 interview, famed television presenter and naturalist Sir David Attenborough stated, “We are a plague on the Earth. It’s coming home to roost over the next 50 years or so. It’s not just climate change; it’s sheer space, places to grow food for this enormous horde. Either we limit our population growth or the natural world will do it for us, and the natural world is doing it for us right now,” (Gray, 2013). Climate change can be interpreted as a natural response of the planet's immune system aimed at eliminating the disease that is humankind. Current vast, interlinked industrial energy and food systems are parasitic to the planet, with tumor-like metropolises growing and consuming more resources as population increases. Corporations are drilling deeper for fuel and plowing land with fewer farmers, more machines and less crop diversity—especially in the United States—which simply prolongs and intensifies many of humanity and the biosphere's greatest problems. With the ongoing and worsening warming of the earth accepted as fact by nearly all scientists—not to mention the finite nature of the fossil fuels humans depend on—it may seem that humanity is doomed. But standing in Terry and Sandra Stapley's aquaponic greenhouse, one feels part of a new, futuristic harmony with nature. Lush, dense greens float on white polymer rafts with their roots submerged in water. Trout and koi swim peacefully in rearing tanks, excreting nutrients into the water to be filtered throughout the plant troughs. It's a closed loop system. The fish and plants work together in a nature-mimicking cycle with few inputs and high yields called aquaponics; an exciting solution to many of the struggles of organic agriculture and negative effects of industrial agriculture. This new method of cultivation is capable of providing sustainable, healthy food the world over while decreasing dependence on fossil fuels.

          As shown in the film Dirt! The Movie, soil depletion is a huge issue that is caused by agricultural practices such as monoculture and overgrazing. Extended supply lines and the copious use of harsh chemicals and synthetic fertilizers made from fossil fuels—among many other actions—utilized by the dominant agricultural system result in a myriad of environmental issues and greenhouse gas emissions (Lin 3, Table 1). Despite an exciting rise in natural or organic urban and rural local farms in communities (Kinkead 367), sustainable and free range agriculture face difficulties in competing with and ultimately replacing the existing, centralized “big ag” system. The problem is that the industrial food system is capable of supplying huge yields of food (especially meat and corn) per acre because it feeds cows, pigs and chickens with genetically modified corn feed and crams them together while pumping them with antibiotics and hormones, as criticized by the 2009 documentary Food, Inc.

          A highly viable way to rival yields and productivity of industrial, inorganic factory farms in the United States and elsewhere is to employ new aqquaponics. Aquaponics is a nearly seamless merging of aquaculture—the farming of fish—and hydroponics—the process of growing plants with water and added nutrients but no soil. The isolated problems with each of these techniques are that dirty water riddled with fish waste in an aquaculture system must be treated and phased out frequently to keep the fish healthy, while nutrients needed for plants to grow must be consistently added to hydroponic systems while carefully monitoring acidity. By mixing the two methods, both issues can be solved. In fact, the very problems of each create a collective solution when combined. While raising fish in an aquaponic tank, water containing ammonia from fish exhalation and excrement is pumped to under rafts of plants with protruding roots or into a grow bed full of porous rocks or clay where planted have laid roots. Naturally occurring bacteria in nature break down the ammonia in the fish waste into nitrate nutrients for the plants, which simultaneously absorb the nutrients and clean the water. After the waste has been converted into nutrients and consumed, the newly cleaned water is pumped back into the fish tank. This process is repeated over and over again in a tight loop. Aquaponics systems yield more fruit and vegetables in less time than traditional gardening methods, not to mention the abundance of fresh fish that can also be harvested from the system. It is a very profitable system for producing food.

          The only inputs to an up and running aquaponics system are fish food and a modest amount of electricity to run the pumps and heat the fish tank water in some situations. Fish food can come in the form of feed pellets, but in order to more completely close the system's loop and increase profits and sustainability, aquaponic growers can grow their own algae to feed to the fish. The electricity used to keep the water flowing can easily be provided exclusively by a small solar array. 

          Basic human needs consist of food, water and shelter. World food production faces many challenges in the near future. Droughts are becoming more widespread; California, a major supplier of U.S. fruits and vegetables, is currently in the midst of a water crisis. With an aquaponics system, much more food can be provided in a certain amount of space than with conventional gardening. It also uses only one tenth of the water of a home garden because instead of soaking into the soil the water is directly fed to plant roots and recycled in the system (Stapley). Home-made aquaponics systems are quite affordable to construct. All one needs is a Rubbermaid tub, a filter, PVC pipes, and Styrofoam rafts or a grow bed with little rocks and plant seeds. Professionally manufactured aquaponics systems are already on the market from aquaponics companies such as Nelson & Pade starting at about $300 and going up to thousands of dollars depending on design and size. The systems can easily pay for themselves within a few years and keep on giving, much like solar panels.

In fact, when coupled with home solar panels, aquaponics can help any home become completely self sufficient in terms of food and electricity, cutting off support to fossil fuel operations and corporate agriculture. This provides independence and steady returns while fostering the longevity of Earth's biosphere, including humans and the many other species that inhabit it. There is no compelling reason why all American homeowners that can afford it should not have solar panels and aquaponics systems for their homes right now. One cause for the lack of widespread implementation of aquaponics—in addition to its novelty—may be lack of awareness, since aquaponics is a relatively new field developed in the past few decades. An Aquaponics Journal has been in circulation since 1997 (Rakocy 1), but backyard, home and larger scale aquaponics systems are gaining increasing traction in recent years. With the advent of aquaponics, Americans and people all over the world have the chance to take advantage of a simple method to become self sufficient in food and energy. Indeed, aquaponics projects hold significant promise for island nations with little arable land who must import much food such as Hawaii, Haiti and Australia. Dr. James Rakocy, known as the father of aquaponics, developed the first large scale aquaponic facility at the University of the U.S. Virgin Islands, which provides significant sums of food for the people of St. Croix.

          One of the biggest perks of aquaponic systems is that they require less effort to maintain than other forms of food production. Regarding this, Rakocy and colleagues wrote, “Aquaponic systems are easier to operate than hydroponic systems or recirculating fish production systems because they require less monitoring and usually have a wider safety margin for ensuring good water quality,” (16). Enthusiastic witnesses to the ease, efficiency and productivity of aquaponic systems are numerous. “It practically runs itself,” said Terry Stapley. “All I have to really do is feed the fish and check the levels. And the best part is there's no weeding, watering and back-breaking bending over like in gardening.” Canadian aquaponic YouTube video blogger JT Bear published a video titled AquaponicGardens & My Opinion After Two Years in which he remarked, “This is a fantastic method of gardening. Almost anybody, anywhere can do it. It uses the same water again and again and again so even with the water restrictions that we have here in the valley that I live—and they get pretty harsh with their water restrictions—it's not even a blip on our water bill. Any other form of gardening is almost just a waste of time by comparison.” With this little maintenance required, aquaponics becomes more attractive as a non-intensive food generating technique. It can support individual families, neighborhoods, villages and especially cities if urban rooftops are utilized as aquaponic space. Rooftop gardens are already springing up in cities, but if they were made to be aquaponic gardens they could be much more efficient an self sustaining while producing a valuable source of protein. The bounty of an aquaponic greenhouse is a lush sight to behold. Because there is no soil, plants can be planted much closer to each other. The result is a monumental yield per square meter of food. Space and rain or irrigation water need no longer be decisively limiting factors as they are with gardening or farming.

          By implementing aquaponics technology in communities around the world, many of the world's problems can be solved. Hunger may have met its match. Projects to set up aquaponics in third world countries—especially in over-fished or desert areas—are already underway. The systems work quite well in Africa where algae can be grown in water and abundant sunlight to provide all the food the fish need, completely closing the sustainability loop with no need to purchase feed. Because it takes less area, aquaponics could replace factory farming without causing deforestation. Being in an aquaponics greenhouse feels good. Many online video bloggers describe feelings of peace when they tend to their aquaponics systems, often coming by just to relax. Stapley said, “I like to come in here in the middle of the night when the fish swim up to toward the surface so you can really see them well.” Although systems are often in greenhouses, there is a certain transcendentalist quality to them. It is easy to sense a Jeffersonian pride in Stapley's words and JT Bear's videos. 

          The goal of many aquaponic growers is to provide healthy food for themselves and their families and communities. The Stapleys can feed as many as 20 other families with their two greenhouses. This is a large reduction from the amount of people industrial farmers in the midwest can feed, but the Stapleys do not just provide one crop to be exported across the country. They sell the large amount of fish and produce that they do not eat themselves or share with family members to the farmer's market. They can provide local people with a complete diet of organically grown vegetables, fruit and fish.

          There are very few drawbacks to aquaponics, but they are worth addressing as they can often be worked around. For instance, the construction of an aquaponics system may be difficult for the layman that cannot afford a prefabricated model, but hundreds of videos on YouTube and online forums provide tutorials and tips for constructing a home made system for little to no cost. Ammonia, nitrite, oxygen, nutrient and temperature levels oughted to be checked regularly and balancing the ratio of plants to fish is important (Rakocy 9). However, if built and stocked well from the onset, the system will have few problems and practically run itself. Due to environmental stress such as harvesting, rising or falling water temperature or bacteria, some fish may die prematurely or contract disease. On memorial day in 2014, Terry Stapley's grandchildren were playing in his basement while the adults were outside. His grandson accidentally flicked a switch on the circuit breaker that shut off power to one of his aquaponic greenhouses. When Stapley went out to feed his trout later that day, they were all floating on the top of the water, dead. A pump must stay running in most aquaponic systems to circulate the water, but these pumps often consume about the same amount of electricity as an incandescent lightbulb (Stapley). Air stones are also recommended to keep the water oxygenated. Overall, the amount of electricity required to maintain an aquaponic system is mild, and aquaponics is overall less replete with problems than outdoor farming.

          In terms of fish to choose for an aquaponic system, tilapia are considered the most suitable fish for aquaponics (Rakocy 2), but there is some controversy among nutritionists surrounding their healthiness due to a high Omega-6 to Omega-3 fatty acid ratio, especially when fed corn and soybean diets in large aquaculture operations. This may be solved by using a high protein and omega-3 feed. High protein and Omega-3 fish meal is negative because it contributes to over-fishing of the oceans, but a sustainable alternative can be found in brine shrimp. Terry Stapley buys his fish food from Skretting USA's headquanters in Tooele for $1 a pound. Skretting is the world's leading producer of fish and shrimp feed, harvesting brine shrimp and fly larvae from the Great Salt Lake. A pound of feed lasts him one week while feeding roughly 300 fish. Culturing phytoplankton high in Omega-3's as part of aquaponics systems is also a way to nutritionally close the loop that is already being done. If this does not improve tilapia Omega-3 levels enough, other fish can be utilized in the system that are naturally higher in helpful fatty acids, such as Perch or Trout (which are also popular varieties in aquaponics today). Perch are common in Australia, while in North America trout can tolerate colder temperatures but can be “finnicky” when it comes to warmer temperatures (Stapley). Nutrition aside, many growers don't even harvest their fish, simply utilizing them as fertilizer machines, decorations or pets. Koi are a popular decorative fish for aquaponic systems. Pet store goldfish can also be inexpensively used in a vegetarian aquaponic system and grow to large sizes.

          Aquaponics simulates processes occurring successfully in nature for thousands of years to create a closed loop, sustainable food production machine. In essence, it is a low maintenance system that utilizes biofiltration to churn out food. Aquaponics is a highly efficient, harmonious plant growing system that practically runs itself, and if fish are harvested it is quite possible for a family or community, even every person on Earth, to be fed entirely with aquaponic protien, fruits and vegetables. The speed and quality of plant growth in aquaponic systems are remarkable. When coupled with water, oxygen, sunlight, and carbon dioxide and several minerals, the fish provide the nutrients needed for plant growth, creating an extremely fertile system. As one example, Stapley had a young soil based peach tree that seemed to have died. On a whim, he decided to simply place it directly in the aquaponic water trough without a grow bed or raft. Within weeks the tree had turned green once more and was growing healthy leaves. Aquaponic growers report more than doubled rates of growth compared to soil cultivation. Aquaponics has every bit of potential needed to be at the forefront of a sustainable world food system. From gold fish in a rubber tub with plants in netted pots in a Styrofoam raft to large scale operations with trout or tilapia to feed hundreds of people, anyone can be an aquaponic grower. It offers a groundbreaking way to harness principles of nature to produce organic food quickly, densely and profitably that is healthy for humans and healthy for the environment.

Works Cited

JT Bear. “Aquaponic Gardens & My Opinion After Two Years.” YouTube. 23 Aug 2013.

Dirt! The Movie. Dir. Gene Rosow and Benenson, Bill. Narr. Jamie Lee Curtis. Common Ground Media, 2010.

Food, Inc. Dir. Robert Kenner. Narr. Peter Zinger. Magnolia Pictures, 2009.

Gray, Louise. “David Attenborough: Humans are plague on Earth.” The Telegraph. Telegraph Media Group, Jan 2013.

Hern, Warren A. “Has The Human Species Become A Cancer On The Planet?: A Theoretical View Of Population Growth As A Sign of Pathology.” Current World Leaders. Vol 36, No. 6, pp.1089- 1124. Dec 1993.

Kinkead, Joyce, Evelyn Funda and Lynne S. McNeill. Farm: A Multimodal Reader. Utah State University Department of English. Fountainhead Press, 2014.

Lin, Brenda B, M. Jahi Chappell, John Vandermeer, Gerald Smith, Eileen Quintero, et al. “Effects of industrial agriculture on climate change and the mitigation potential of small-scale agro-ecological farms.” CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources. 6 No. 020. CAB International, 2011.

Rakocy, James E., Masser, Michael P., and Losordo, Thomas M. “Recirculating Aquaculture Tank Production Systems: Aquaponics—Integrating Fish and Plant Culture.” Southern Regional Aquaculture Center. SRAC Publication No. 454. Nov 2006.

Stapley, Terry. Personal Interview. 10 April 2015.

Field Notes, Deseret Peak Aquaponics

Terry Stapley:

We got our trout from Coal Creek Trout Farm. We get all our fish feed from Screetings in Tooele, which harvests Brine Shrimp from the Great Salt Lake. It's $1 for 1 lb, and I use about 1 lb a week.

My rocket stove keeps the water for the plants warm in winter. They like it to be at about 62 to 65 degrees Fahrenheit. We use coconut fiber for seeding, then net pods in the rafts as the seedlings grow. Rafts are the most economic and efficient method. We made our rafts out of Dow corning blue board. Paint it white with latex bright white paint because UV rays will break down a blue board if its not painted. We grow Swiss Chard, Russian Red Kale, Lacinato Kale, Blue Curly kale, Lettuce, Strawberries,Tomatoes, Raddishes and a lot of other varieties of leafy greens and vegetables.

For the trout, I've experimented with water from 60 to 64 degrees. The small ones are about 7 to ten inches. The big ones can get 15 to 20. You have to put iron in the water for the plants, because that's the one thing the fish don't produce. It usually comes from the dirt. Use FeEDDHA. The double D variety is key. I use Ferriplus.

We started with a dozen koi in the water trough, then got trout to go here. Water from the koi pond would drain into the trout trough to help the trout adjust.

On memorial day of last year, my grandchildren were at our house playing in the basement while all of the adults were outside. One of my grandsons somehow flipped the circuit breaker for the power to the greenhouse. When I came to check on the trout later that day they were all floating on the surface, dead. Trout are DELICATE. Very finicky. Koi are hardier and more lethargic.

This week we're harvesting lettuce for a Utah's Own event.

As far as pests go, aphids come into the undergrowth of plants. We've had black gnats but they haven't bothered the plants much. We bought African Cichlids—little blue fish that feed on insect larvae and algae on or in the water. We put them underneath the plant rafts. Another problem is butterflies. They will lay eggs then the hatched caterpillars will eat the leaves of produce.

The pump we use to run the whole system is 75 Watts. We also have a small air pump to get oxygen into the water for the fish.

It cost us 15 grand to get this 20x55 ft greenhouse built and up and running. The metal frames and sheeting cost about $5,000. The tank is 1,800 gallons braced with 4 by 4 posts 2 feet deep into the ground. The other, smaller 16x40 ft greenhouse we built first only cost 5 grand altogether.

When the water runs out of the heater and into the first plant trough, the temperature is 66 degrees Fahrenheit. By the time it gets to the next trough it's 64, then 62, then 61 by the time it gets to the trout. So it's about a 2 degree change per trough. Trout are okay with 50 degrees. They survived at 48 no problem. They'll tolerate 65, that's what I'm keeping it at now for the plants. Early on my goal was to get the water temperature up to 70 degrees because that's ideal for the plants, but when it got there I had 11 floating trout. So we dropped it back down to 65. The plants grow a little slower at that temperature but it keeps the fish alive. The tricky part is finding a temperature that works for the plants and the fish. Koi like a warmer temperature than trout. Mainly aquaponics uses Tilapia, which are a great fish for aquaponics and can tolerate higher temperatures, but they're currently illegal in Utah.

I made a heat sink to blow warm air into the greenhouse by putting rocks and mud at the exhaust of the rocket stove. The vacustack goes to the chimney. Any breeze creates suction. At night time the combustion process slows way down when you shut it. There are still embers in the morning.

I started harvesting the fish a month ago. The system takes 90 lbs of fish to operate with enough nutrients for the plants. Since we're at more than that we just harvested 15 trout for the Farmer's market. Out of the 350 trout in the batch we got 50 were tiger trout. The rest were mostly rainbow. We had a lot of jumpers at first. So I put in exterior studs with insulation and plastic to keep them in.

If you were to start an aquaponic system in June, you'd have the first harvest by August, then the next one by October. It's only a 6 to 8 week cycle from planting seedlings to harvest.

This Kale here is old, but we keep it in so the roots filter the water for the fish. You want to have your starts a coupe inches tall when you put the fish in to filter the water.

Aquaponics is 95% more efficient than planting in dirt. I have to put in a little water to the system every week and a half because of evaporation and the plants absorbing some. When starting a system with city water you have to let it percolate for 3 or 4 days, but we use well water. As you can see, we've pretty much abandoned our dry soil garden because it just doesn't compare to aquaponics.

We put windows up high on one side of the greenhouse and low on the other. If it's 40 degrees outside it can be 90 degrees inside. Right now it it's 65 degrees outside and 90 inside. It was 110 in here this morning before I opened the windows. Bacteria are throughout the whole system. You could try putting the fish in the troughs with the plants on top. The roots are always floating.

We keep tomatoes alive by covering them up at night. Carrots didn't work. Neither will tuber plants.

We sell whole, gutted trout from $7 to $10 each. We've got about 300 fish now. 50 koi and about 250 trout. 11 ounces each. We have 179 lbs of fish In the tank, and he only needs 90. when they get bigger, the fish get closer and end up floating.

Lettuce can make it down to 25 degrees. We just keep everything above the water covered if it gets cold. The roots are never going to freeze cause they're sitting in 65 degree water with the rocket stove.

Our peach tree died and I said well heck let's just put it in the aquaponics system. As you can see, it came right back to life. It's just sitting in the water and it's green and thriving. I can grow 4 times the amount in here than I did with 3 raised beds, and you can only harvest once a year in soil. With aquaponics you harvest every 6 to 8 weeks.

It's all organic. We're not certified organic but it's completely natural and organic. The farmer's market is grower direct, no inspection. Anybody who understands aquaponics will realize that aquaponics can only be organic. If you put in any pesticides it will kill the fish.

One of the best parts for me is NO WEEDS! It's so nice. No back breaking labor constantly bending over. You just have to check on the system every once and a while and feed the fish. Other than that once its up and running it takes very little maintenance and upkeep.

The only thing that's not completely renewable for us at this point is basically the fish, because trout will only propogate in water below 65 degrees.

I've thought about installing glass and putting up lights for display so you can see the fish. Sometimes I like to come here in the middle of the night when they swim near the surface and you can really see them.

We're on the 2^nd harvest of the same plants now. We harvested these same plants in September and now we're harvesting them again after they were cut and grew back.

We try not to give anybody sub par stuff. All that (gesturing to scottish blue kale) is just excellent.

Last farmer's market we sold $400 of stuff. It will take a while to pay back the greenhouses.

We smoke the fish we harvest for ourselves in a wood fire grill and it is just to die for.

You could do this in a pond, put down a pond liner and just pump the water out of it. We thought about doing that, then pumping the water to 5 greenhouses. But then what happens when it gets cold? How do you protect the pond?

There are several other aquaponics operations in Utah. There's a guy in alpine Utah. He uses an electric water heater to warm the water for the fish and plants.

The air pumps we use are equivalent to a light bulb and a half of wattage. The water pump the same as one light bulb. The only expense is that and fish food. I know a guy who does simply hydroponics and he has to dump all the water when his crop is done because the water is too hot with fertilizers for anything to start afresh. You don't have that problem with aquaponics.

Alpaca fiber is $8 an ounce. Each animal will give you at least 5 lbs. Alpaca is hypoallergenic, warmer and more waterproof than wool. My wife makes hats, mocassins, gloves, jackets, all kinds of things. I have a pair of alpaca socks and my feet have never gotten cold in them. You just arrange the alpaca cloud how you want it to be and it comes out of the machine we have interwoven on the other side. You We have goats for milk.

Next on the list is a gasifier. We'd put alpaca poop in it, make a soup out of it, and out of that you can make methane gas to run a generator with.

We make kale chips all the time. They're great. Just put some olive oil and salt on them and put them in the oven at 375 for 15 minutes and they're ready to go.