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What is Aquaponics?
Are you wondering “what is aquaponics?” The most simple definition is that it is the marriage of aquaculture (raising fish) and hydroponics (the soil-less growing of plants) that grows fish and plants together in one integrated system. The fish waste provides an organic food source for the growing plants and the plants provide a natural filter for the water the fish live in. The third participants are the microbes (nitrifying bacteria) and composting red worms that thrive in the growing media. They do the job of converting the ammonia from the fish waste first into nitrites, then into nitrates and the solids into vermicompost that that are food for the plants.
In combining both systems aquaponics capitalizes on the benefits and eliminates the drawbacks of each.
The problems with traditional soil-based gardening
- The weeds
- The amount of water required
- The soil-borne insects
- The heavy digging, the bending, the back strain
- The the bunnies, the raccoons, and other 4-legged pests
- Knowledge required to know when to water, when and how to fertilize, and what is the composition of the soil
These issues are all solved with hydroponics, but hydroponics has problems of its own
- Traditional hydroponic systems rely on the careful application of expensive, man-made nutrients made from mixing together a concoction of chemicals, salts and trace elements. In aquaponics you merely feed your fish inexpensive fish feed, food scraps, and food you grow yourself.
- The strength of this mixture needs to be carefully monitored, along with pH, using expensive meters. In aquaponics you carefully monitor your system during the first month, but once your system is established you only need to check pH and ammonia levels weekly or if your plants or fish seem stressed.
- Water in hydroponic systems needs to be discharged periodically, as the salts and chemicals build up in the water which becomes toxic to the plants. This is both inconvenient and problematic as the disposal location of this waste water needs to be carefully considered. In aquaponics you NEVER replace your water; you only top it off as it evaporates.
- Hydroponic systems are prone to a disease called “pythium” or root rot. This disease is virtually non-existent in aquaponics.
The problem with recirculating aquaculture
- The tank water becomes polluted with fish effluent which gives off high concentrations of ammonia. Water has to be discharged at a rate of 10-20% of the total volume in the tank daily. This uses a tremendous amount of water. Again, in an aquaponics system you never need to discharge your water
- This water is often pumped into open streams where it pollutes and destroys waterways.
- Because of this unhealthy environment fish are prone to disease and are often treated with medicines, including antibiotics. Fish disease is rare in an aquaponics system.
How aquaponics changes the game
- Waist-high aquaponics gardening eliminates weeds, back strain and small animal access to your garden.
- Reuse resources currently considered “waste”. In aquaponics there is no more toxic run-off from either hydroponics or aquaculture.
- Aquaponics uses only 1/10th of the water of soil-based gardening, and even less water than hydroponics or recirculating aquaculture.
- Watering is integral to an aquaponics system. You can’t under-water or over-water.
- Fertilizing is also integral to an aquaponics system. You can’t over-fertilize or under-fertilize.
- Gardening chores are cut down dramatically or eliminated. The aquaponics grower is able to focus on the enjoyable tasks of feeding the fish and tending and harvesting the plants.
Instead of using dirt or toxic chemical solutions to grow plants, aquaponics uses highly nutritious fish effluent that contains all the required nutrients for optimum plant growth. Instead of discharging water, aquaponics uses the plants and the media in which they grow to clean and purify the water, after which it is returned to the fish tank. This water can be reused indefinitely and will only need to be replaced when it is lost through transpiration and evaporation. Two primary methods of aquaponics growing are most widely in use today.
- The raft based aquaponics growing system uses a foam raft that is floating in a channel filled with fish effluent water that has been through filtration to remove solid wastes. Plants are placed in holes in the raft and the roots dangle freely in the water. This method is most appropriate for growing salad greens and other fast growing, relatively low-nutrient plants.
- The second method is called media based aquaponics because plants are grown in inert planting media (gravel, expanded clay pellets, coir, etc.). The media provides both the biological (ammonia based waste) and mechanical (solid waste) filtration, so requires far less maintenance than raft-based systems. Large, fruiting plants are also grown much more successfully in media based systems than in rafts.
- The third method is called hybrid aquaponics, which is a combination of the two. The media beds become the pre-filter for the solid waste before the water enters the raft systems. This hybrid system style is the focus of The Aquaponic Source’s AquaBundance systems because it provides planting flexibility, high productivity and low maintenance.
History of Aquaponics
- Long before the term “aquaponics” was coined in the 1970s the Aztec Indians raised plants on rafts on the surface of a lake in approximately 1,000 A.D.
- In modern times aquaponics emerged from the aquaculture industry as fish farmers were exploring methods of raising fish while trying to decrease their dependence on the land, water and other resources.
- Traditionally fish were raised in large ponds, or in netted pens off ocean coastlines, but in the past 35 years much progress has been made in recirculating aquaculture systems (RAS).
- The advantage of RAS is that fish can be stocked much more densely: up to of a pound of fish per gallon of water, thus using only a fraction of the water and space to grow the same amount of fish as pond or netting based systems.
- The disadvantage is the large amount of waste water that quickly accumulates.
In the 1970s research on using plants as a natural filter began, most notably by Dr. James Rakocy at the University of the Virgin Islands.
- The first large scale commercial aquaponics facility, Bioshelters in Amherst, MA, was established in the mid-1980s, and it is still in operation today.
- Home based aquaponics owes its origin in the early 1990s to Tom and Paula Speraneo of S&S Aquafarms in West Plains, MO. The Speraneo’s diligently refined a media bed growing technique that was more appropriate for smaller systems, and wrote a how-to manual that became a spring board for many home based systems build through-out the world.
- Meanwhile, on the other side of the world in Australia interest in home aquaponics was taking off because aquaponics is a way to solve the drought and poor soil conditions that the Australians have to contend with. Joel Malcolm led the movement by starting a popular forum (Backyard Aquaponics) and creating and selling aquaponic systems designed specifically for homeowners. He was joined by Murray Hallam of Practical Aquaponics, who also runs a forum and is best known for his series of entertaining DVDs on home aquaponics.
- In January, 2010 the Aquaponic Gardening Community was formed, and it has since become the largest online gathering place for aquapons in North America.
- In September, 2011, the book Aquaponic Gardening by Sylvia Bernstein was introduced at the first annual Aquaponics Association Conference in Orlando, Florida. It was the first time that a complete guide to designing, building, starting and maintaining a media-based aquaponics system had been available. Within a month the book was the best selling gardening book on Amazon.com and within the first year the book was printed four times and sold over 30,000 copies.
- At that same conference the Aquaponics Association was officially created with Gina Cavaliero of Green Acre Aquaponics and Sylvia Bernstein of The Aquaponic Source as the founders and inaugural Chair and Vice Chair. The Association’s mission is to promote aquaponics, and to continue holding annual conferences so aquaponics practitioners from around the world can gather once a year to exchange ideas and learn from each other.
- With the Aquaponics Association increasingly focused on commercial farming, in August of 2014 the first Aquaponics Fest was held in Longmont, CO for home and school aquaponic gardeners.