What the heck is aquaponics?

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Photo courtesy of AIDG

If you hang out with gardening hippies, you may hear the term “aquaponics” thrown around. So, what the heck does it mean?

Aquaponics is a gardening technique designed to maximize water efficiency and minimize the need for fertilizers. The technique involves farming and raising fish in an integrated system, where fish produce natural fertilizer while plants filter and oxygenate the water. A well designed aquaponic system requires minimal supervision and creates two desirable crops – fresh herbs and fish. The components of the system produce synergy: fish and plants grow more efficiently together than they would in separate tanks.

…when the aquaponic system is fully operational after six months, it leaps ahead of inorganic hydroponics. This leads to earlier maturity of greenhouse crops under aquaponics and much heavier cropping.

Aquaponics is a portmanteau of the words Aquaculture and Hydroponics. It gets improved results due to the symbiotic behavior of several living organisms. The plants and fish complement each other, but a lot of the productivity depends on integrating bacteria and microorganisms in the system. Bacteria convert fish waste into useful nutrients for the plants, and phytoplankton produce food for the fish.

Aquaponics is an old concept – the ancient Aztecs and Egyptians used the technique with various plant and fish species. In China and Thailand, it’s traditional to raise fish in flooded rice paddies. Since the 1970’s, several universities have been developing modern techniques and applying scientific method to get the greatest performance.

Compared to conventional agriculture, aquaponics is a huge water saver. On a farm in Oklahoma, it takes 6 gallons of water to grow a head of lettuce. At 24 heads per case, that means raising 1,250 cases of lettuce using conventional methods would require 180,000 gallons of water. A DeepWater aquaponic system uses about 16.1% as much water to create the same results (and it generates more than 3,600 pounds of fish fillets and 7,400 pounds of fish scraps for use as fish feed or fertilizer).

Here’s some more information on aquaponic water efficiency, comparing aquaponics to hydroponics and conventional farming techniques:

Estimated total value of output is then A$405,000 ($305,491 USD) — which represents water use efficiency of around 173 liters/A$100 of production.

This compares very favorably with the Australian commercial hydroponics figure of 600 liters of water used per A$100 of production.

There are many different aquaponic systems, but two major schools have emerged. These two approaches look very different, and each is best for certain crops or locations. These competing systems are Deep Water Aquaponics and Reciprocating Aquaponics. The primary difference is where the plants are positioned. In Deep Water Aquaponics, plants float on top of a pond of water (usually inside styrofoam rafts with holes for their roots). In Reciprocating Aquaponic systems, the plants are outside the pond and water is carried to their roots along irrigation tubes.

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Photo courtesy of Aria Fotografia at Flickr.com

  • Deep Water Aquaponics
  • Deep Water Aquaponics is also known as Raft Culture Hydroponics or “the UVI system”. One of the main proponents of this type of hydroponics is Dr. James Rakocy of the University of the Virgin Islands. He offers training courses and maintains an aquaponic demonstration facility with 15 full scale systems that have been in continuous operation for several years. The system is very productive and water efficient:

    UVI’s aquaponics system, which occupies an eighth of an acre and uses 29,000 gallons of water, can produce annually 11,000 pounds of tilapia and 11,000 pounds of basil or 1,250 cases of lettuce.

    Here’s a cool photo-tour of the UVI system. Note – the fish are grown in separate tanks to prevent them from eating the roots of crop plants.

  • Reciprocating Aquaponics
  • Reciprocating Aquaponics is also known as “Flood and Drain” or “Ebb and Flow”. This system uses gravel or sand beds to filter water from fish tanks, and then irrigates plant beds using irrigation pipes (or positions plant roots inside the irrigation pipes). The result is a system with more control over temperature and humidity. Some plants that don’t do well in hydroponic systems thrive in these conditions, because their roots are protected against rotting. Biofiltration beds also allow more microbial activity in a smaller area, which is important when space is limited. On the flip side, the filtering media will get clogged over time, and cleaning it is hard work.

    This type of aquaponic system was developed by Mark McMurtry and many other pioneers. Several different ebb and flow systems have been built since the mid 1980’s.

    If you’re looking for a cool way to renovate the pool in your back yard, or if you want to do more with the rain water in your rainbarrels, there’s no time like the present to check out an aquaponic system.

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    Photo courtesy of ideonexus at Flickr.com

    How to plant a victory garden

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    Photo courtesy of Sunfell at Flickr.com.

    Everything old is new again. This is doubly true for trends that never went completely out of fashion, like vinyl records and Victory Gardens. Originally conceived during World War I as a way to ensure food supplies for troops, these community gardens took off in a big way during the second World War. By 1944, up to 40% of the vegetables on American tables came from a Victory Garden.

    Now, with the rising price of staple foods, increasing awareness of the environmental cost of industrial farming, and increased interest in self sufficiency and independence, Victory Gardens are making a serious comeback. The Smithsonian Institute has a new exhibit on Victory Gardens, and vegetable rows are replacing ornamental bushes nationwide.

    Modern-day Victory Gardens look a little different – gardeners are now blogging about their successes and even using Twitter to send gardening updates!

    Success with Victory Gardens is snowballing into more awareness of Community Supported Agriculture (CSA). Urban food pantries are stocking up with fresh fruit gleaned from “ornamental” trees. Believe it or not, some HOA’s are embracing community gardens. There’s even a campaign to start a Victory Garden on the White House lawn:

    Benefits of a victory garden:

    • Cut grocery bills
    • Gain access to fresher food
    • Boost vitamins in your diet
    • Increase the health of your soil
    • Insure against food shortages
    • Reduce exposure to pesticides and other chemicals
    • Avoid disease (or ensure access to your favorite veggies if an outbreak occurs)
    • Preserve oil supplies / reduce dependence on foreign oil
    • Grow produce for sale or gifts

    So, let’s say that you’ve been bitten by the Victory Gardening bug. Where to begin?

    It can be a bit daunting to start your first Victory Garden. There’s a lot to learn about soil, planting seasons, and local weather conditions. Hit the books! The library is a good place to start – a little bit of research can go a long way in getting the best results. As the old saying goes, an ounce of preparation is worth a pound of perspiration. Your state’s Extension Office can also be a good source of information and expert advice.

    Try looking for help from your neighbors – local gardening clubs often know the best times to plant and which species do best in your area. Find a local Gardening MeetUp, and you’ll find a pool of knowledge and maybe even people willing to lend you seeds or cuttings from their favorite plants. No matter which plants you choose, PBS is a great resource for beginner gardeners.

    In the past, Victory Gardens were all laid out from a universal template. That didn’t work out very well for people who tried to grow the same plants in California as they did in Maine and Florida. Instead of a cookie cutter layout, you should tailor your garden to local conditions. Work with your climate to choose the best plants. For example, even if you love rice, it may not make sense to grow rice if you live in the middle of the desert.

    We’ve learned a lot in the last 50 years, and it’s easier to start a vegetable garden in your yard than ever before. Incorporate this knowledge in the layout and composition of your victory garden, and you can achieve amazing results. Our grandparents didn’t have much practical experience on designing to minimize erosion or using cover crops that naturally fertilize the soil, but there’s a wealth of useful information on these techniques. Here are some other research topics that you might want to consider:

    Even if you have limited space or no yard, Victory Gardens can be grown in containers and indoor planters. Hanging planters can turn any patio or balcony into a vertical garden.

    If you don’t have a patio, many plants will thrive in window planters or grow boxes. There are also light boxes and grow lights that can turn the deepest, darkest basement into an oasis of life. Indoor plants not only make rooms beautiful – they also can help reduce sick building syndrome by providing fresh air and absorbing indoor pollutants.

    Not a gardener? No problem. There are entrepreneurs eager to turn other people’s yards into gardens. Also, there are other steps you can take to promote food safety and sustainability.

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    Photo courtesy of mental.masala at Flickr.com.

    Make eco friendly choices at the cafeteria


    Photo courtesy of Drunken Monkey at Flickr.com.

    When you visit the buffet line, how often do you think of the planet? If you visit the cafeteria on a regular basis, the choices you make can really add up.

    At the soda fountain, are styrofoam cups the only option? Each cup weighs about 10 grams – that means a cup a day adds up to about 5 and a half pounds of styrofoam per year. You can keep that styrofoam out of landfills by bringing in your own cup, or suggesting that your cafeteria offer re-usable cups (you might even be able to get a promotion – just point out how much the company can save on materials and waste disposal costs).

    The way that you fill your plate can also make a difference. If you fill your plate halfway and then go back for seconds on a fresh plate, that doubles the amount of water needed to wash your dishes. It’s best to make just a single trip and give your stomach time to settle. That way, you wont be in the middle of eating a second plate when your hunger runs out. Wasting food can have a huge impact on the environment too – for example, a quarter pound burger can take 100-1,300 gallons of water to produce.

    Some college cafeterias are even getting rid of lunch trays. By eliminating trays, they expect to save megawatts of power and millions of gallons of water that are normally used to wash the trays. There’s also a hope that diners will be encouraged to take smaller servings from the cafeteria line, reducing waste, overall food costs, and health issues related to weight gain.


    Photo courtesy of Tkrecu at Flickr.com.

    The Sahara desert is reaching north into Spain



    Photo courtesy of DanielKHC at Flickr.com.

    Droughts are a worldwide problem, with water in short supply in many different countries. Australia and Spain are both suffering through record breaking droughts right now. It hasn’t gotten much attention in the US, but rainfall in Spain is at its lowest level in 40 years. This comes at a time when population is booming and per capita water use is rising.

    Water use is a very emotional issue in Spain, and tensions are running high between neighboring cities and regions. Opinions are divided largely along geographic lines; many people living in the southern provinces favor redirecting water from the north (where the drought is less severe). No one in the North wants to sacrifice their water rights to support wasteful behavior though, and water redirection projects face strong opposition. To break this logjam,

    …the government is building more desalination plants, adding to the more than 900 already in Spain – the largest number in any one country outside the Middle East.

    There is some concern that these energy intensive desalination plants will drive up the price of water while also creating even more climate change. It’s a no-win situation, like trying to prevent an avalanche by running a snow maker.

    Leaders in Spain are looking for a better solution. The country is currently hosting the 2008 World’s Fair in Zaragosa, and the theme of Expo 2008 is “Water and Sustainable Development”. New technologies are on display, including water saving fixtures for the home and agricultural techniques that conserve water. Government programs are encouraging people to adopt these innovations with tax rebates and grants, and if the Spanish are successful in conserving their water, they may be able to stop the desertification of their country. Otherwise, climate change will devastate the environment, with lasting effects on the economy.

    If you get a chance to visit Zaragosa, you’ll see an alternative vision of the future, with clean technology offering jobs and climate security. The best vantage point to view the fairgrounds is atop the 250 foot tall Water Tower building.



    Photo courtesy of Paulo Brandão at Flickr.com.