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 are you spending Earth Hour on March 28th?

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    Photo courtesy of Earth Hour Global at Flickr.com.

    Once a year, environmentalists around the world turn out the lights for an hour. This year, Earth Hour falls on Saturday, March 28th, and many different homes, offices, and government buildings are taking part. The organizers of Earth Hour hope to raise awareness of how much energy we waste with inefficient lighting systems. For one hour a year, everyone can take part and see the beauty of the natural sky that’s lost due to light pollution.

    The World Wildlife Fund and other environmental organizations are hard at work planning activities for Earth Hour 2009, ranging from star watching and recycling events to tree plantings and slumber parties. Find an Earth Hour event nearby, or if there aren’t any, you can plan one yourself with help from the Earth Hour Facebook group!

    Now’s the time to raise your voice and take part. Are businesses and government offices in your town participating in Earth Hour? Check the latest Earth Hour news, and if City Hall isn’t taking part, now is a good time to ask pointed questions of your elected officials. While they’re on the line, why not ask about steps that the city is taking to retrofit energy efficient devices into public buildings and legislation that improves local air quality?

    Maybe it’s time to re-evaluate how we destroy the night sky for the other 8,765 hours of the year…
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    Photo courtesy of fyngyrz 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.

    Invasive species are on the move

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    Photo courtesy of Brewbooks at Flickr.com.

    Mountain ranges, oceans, deserts, rivers, and other landforms divide the world into different regions and zones. These natural barriers isolate plants and animals from each other, and allowed many different species to evolve. Over millions of years, nature found different solutions to the unique situations within each enclave, and we ended up with wildly different ecosystems – each with some plants and animals that can’t be found anywhere else.

    Unfortunately, the walls between these ecosystems are crumbling. The world is growing increasingly flat, with trade and travel between regions occurring every day. Cargo ships from China regularly travel to Seattle and Melbourne, and their bilge tanks can give fish and clams a free ride. Business travelers who step in mud in one airport unknowingly carry bacteria across mountains in a single flight. Tourists often bring exotic flowers home.

    As a result of global trade and travel, many of the plants, animals, and bacteria that were isolated to small areas are now spreading out over the entire world. Some of these organisms are thriving in their new homes, and endangering native plants that were already there in the process. Many elm trees in New York had ancestors in the Netherlands or France, and are dying off due to Dutch Elm Disease. Bees raised in Poland have to worry about parasites that originated in Southeast Asia.

    Invasive species are shaping the news. For example, wood boring insects are threatening the few remaining old growth forests in America, which has led to a shortage of firewood. Strangely, the shortage isn’t due to a shortage of trees. Instead, because these insects love to travel inside dead trees, restrictions were put in place to control the transport of lumber. If you live in an affected area, you may want to check out cured firewood as an alternative. Cured wood is wood that’s been heated in a kiln to dry it out. It’s not only unaffected by the restrictions, but it also has a much higher heating value per pound.

    The Great Lakes are also threatened by invasive species. Zebra muscles and snakefish do not have any natural predators, so they’re displacing many native species in the area. Game fish are threatened, along with industries that use fresh water from the lakes (zebra muscles tend to clog intake pipes). To combat the problem and prevent the introduction of new species, the Federal government has passed restrictions on how ballast tanks are treated.

    Invasive species are also a threat outside the United States. In Mexico City, the iconic Aztec ‘Water Monster’ is facing new threats from exotic fish. This salamander has a long history in the region, but is unable to cope with habitat loss, pollution, and competition from tilapia. Plans are underway to build sanctuaries for the Water Monster as well as native aquatic plants.

    If that doesn’t work, there may be an option B. Researchers at RIKEN research institute in Yokohama, Japan have been successful in cloning mice that were frozen for 16 years. The researchers are still a ways away from using the technique on Woolly Mammoths, but conservationists may someday be able to use frozen tissue samples from other endangered species to bring them back or to supplement genetic diversity within wildlife preserves. Even if invasive species move in and gobble up all the native plants and animals, there’s a hope of reintroducing native species back to their homes.

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    Photo courtesy of serdir (at home) at Flickr.com.

    Green news you can use

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    Photo courtesy of From A Second Story at Flickr.com.

    Here at the Practical Environmentalist, we’re green news junkies. We keep an eagle eye out for the latest science, social, and environmental developments and try to sum up the big picture on your screen. A lot of exciting things are going on right now.

    First off is an uplifting story about how a species was brought back from the brink of extinction. The Aleutian Cackling Goose is one of the few animals that has been successfully taken off of the Endangered Species list, and it was saved, in large part, by the efforts of a single guy. How cool is that? Imagine if every person adopted one of the species on the list!

    Often, when environmental activists work to preserve the environment, they face resistance from developers, local businesses, and sometimes even their own neighbors. Some people fear environmentalism as a force that closes doors and blocks possibilities, others simply oppose change in any form. Yet, new studies are showing that untamed spaces can be a positive force.

    Environmental activism can achieve personal health goals, and benefit public health at the same time. Just like wild animals, human beings are hardwired to appreciate nature. People who spend more time outdoors have been found to recover from stress faster and have stronger immune systems; they also have and lower rates of disease associated with a sedentary lifestyle. Children who spend more time outdoors have lower risks of obesity and they even develop better vision.

    It’s easy to see how land conservation and sustainable agriculture is changing the world, but the spread of composting, non-chemical fertilizers, and free range ranching doesn’t always make the news. For example, did you know that roughly a quarter of the world’s organic farms are in Africa? Growing demand for organic produce is having a huge impact on some of the poorest farmers in the world, and there are still millions of acres of African farmland that use organic techniques which can be improved to be even more productive. Organic crops have the potential to transform Fair Trade and increase food stability in many African countries.

    One last thing – if you have a few moments to kill, Comedy Central has created a really addictive environmental flash puzzle. It challenges you to step into the President’s shoes and prevent global warming with an array of different technologies. After you lay down each puzzle piece, they will morph and interact with other pieces already on the board. For instance, recycling technology will cause disaster if you don’t build up an industrial outlet for the recycled goods. There’s a moral lesson worth taking to heart.

    What do you think the biggest story is right now? Feel free to post comments below and share your green news with the world.