Aquaponics refers to any system that combines conventional aquaculture with hydroponics in a symbiotic environment. In normal aquaculture, excretions from the animals being raised can accumulate in the water, increasing toxicity. In an aquaponic system, water from an aquaculture system is pumped to a hydroponic system where the by-products are broken down by bacteria into nitrates which are utilized by the plants as nutrients. The water is then recirculated back to the aquaculture system cleaned of harmful toxicity's
A Brief History
Aquaponics has ancient roots, although there is some debate on its first occurrence The Aztec cultivated agricultural islands known as chinampas in a system considered by some to be the first form of aquaponics for agricultural use where plants were raised on stationary (and sometimes movable) islands in lake shallows and waste materials dredged from the Chinampa canals and surrounding cities were used to manually irrigate the plants.
What is Hydroponics?
The term "hydroponics" literally means "water working" it is a method for cultivating plants with out soil using only water and chemical nutrients. The earliest published work on growing terrestrial plants without soil was the 1627 book Sylva Sylvarum by Francis Bacon, printed a year after his death. For many years Water culture became a popular research technique and by 1842, a list of nine elements believed to be essential for plant growth had been compiled, and the discoveries of the German botanists Julius von Sachs and Wilhelm Knop, in the years 1859-65, resulted in a development of the technique of soil-less cultivation. In 1929, William Frederick Gericke of the University of California at Berkeley began publicly promoting that water solution culture be used for agricultural crop production. Gericke created a sensation by growing tomato vines twenty-five feet high in his back yard in mineral nutrient solutions rather than soil. He introduced the term hydroponics,in 1937. Hydroponics is derived from a neologism known as geoponica or, that which concerns agriculture, replacing,Geo or earth, with Hydro or water. |
William F.Gericke |
What is Aquaculture?
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish,snails, oysters,crayfish or prawns in tanks, Aquaculture involves cultivating these populations under controlled conditions.The cultivation of fish species is an ancient practice. Ancient Chinese manuscripts from the 5th century B.C. indicate the Chinese practiced fish culture.Egyptian hieroglyphics indicate the Egyptians of the Middle Kingdom (2052-1786 B.C.) attempted intensive fish culturing. Following in the footsteps of the Egyptians, the Romans also developed aquaculture practices as they are known to have cultivated oysters.The culture of oysters established by the Romans is the first known form of aquaculture that has continued in some form or another to the modern day. aquaculture in ancient times involved harvesting immature fish or shellfish and transferring them to an artificially created environment that is favorable to their growth. Carp, in China, thousands of years ago were collected as youngsters and transferred to special ponds where they were grown. As the Egyptians and Romans proved this practice was not limited to carp but was used with many other species such as oysters and other hardy creatures capable of surviving the transfer to the culture ponds. Fish farming in its modern form was first introduced in 1733 when a German farmer successfully gathered fish eggs, fertilized them, and then grew and raised the fish that hatched. To do this, male and female trout were collected when they were ready for spawning. The eggs and sperm were pressed from their bodies and mixed under favorable conditions. After hatching, the fishlings were taken to tanks or ponds in which they were cultivated. Initially this "fish farming" was limited to freshwater fish.Key components to an aquaponics system:
The Fish
freshwater fish are the most common aquatic animal raised using aquaponics, although freshwater crayfish and prawns are also sometimes used. In practice, tilapia are the most popular fish for home and commercial projects that are intended to raise edible fish, although barramundi, silver perch, bluegill, jade perch, trout and catfish are also used. For temperate climates when there isn't ability or desire to maintain water temperature, bluegill and catfish tend to be more forgiving and are suitable fish species for home systems. Koi and goldfish may also be used, if the fish in the system need not be edible.Bacteria
nitrification, the aerobic conversion of ammonia into nitrates, is one of the most important functions in an aquaponics system as it reduces the toxicity of the water for fish, and allows the resulting nitrate compounds to be removed by the plants for nourishment. Ammonia is steadily released into the water through the excreta and gills of fish as a product of their metabolism, but must be filtered out of the water since higher concentrations of ammonia can kill fish. Although plants can absorb ammonia from the water to some degree, nitrates are assimilated more easily, thereby efficiently reducing the toxicity of the water for fish. Ammonia can be converted into other nitrogenous compounds through healthy populations of nitrifying bacteria: |
| Nitrospira |
Nitrosomonas sp. bacteria that convert ammonia into nitrites, and
Nitrobacter sp: bacteria that convert nitrite into nitrate
Nitrospira sp: bacteria that convert nitrite into nitrate
Nitrogen is necessary for all known forms of life on Earth. It is a component in all amino acids, as it is incorporated into proteins, and is present in the bases that make up nucleic acids such as RNA and DNA. Nitrogen gas (N2) is the largest constituent of the Earth's atmosphere, but this form is relatively nonreactive and unusable by plants.Chemical processing or natural fixation are necessary to convert gaseous nitrogen into compounds such as nitrate or ammonia which can be used by plants. The abundance or scarcity of this "fixed" nitrogen frequently limits plant growth in both managed and wild environments. The nitrogen cycle, like the carbon cycle, is an important part of every ecosystem.
Red Worms
Inputs
Fish Food
As in all aquaculture based systems, stock feed usually consists of fish meal derived from lower-value species. Ongoing depletion of wild fish stocks makes this practice unsustainable. Organic fish feeds may prove to be a viable alternative that relieves this concern. Other alternatives include growing duckweed with an aquaponics system that feeds the same fish grown on the system. excess worms grown from vermiculture composting, using prepared kitchen scraps,as well as growing black soldier fly larvae to feed to the fish using composting grub growers are all ways to feed your system.
Water usage
Aquaponic systems do not typically discharge or exchange water under normal operation, but instead recirculate and reuse water very effectively. The system relies on the relationship between the animals and the plants to maintain a stable aquatic environment that experiences a minimum of fluctuation in ambient nutrient and oxygen levels. Water is added only to replace water loss from absorption and transpiration by plants or, evaporation into the air from surface water, As a result, aquaponics uses approximately 2% of the water that a conventionally irrigated farm requires for the same vegetable production.This allows for aquaponic production of both crops and fish in areas where water or fertile land is scarce.
Energy usage
Aquaponic installations rely in varying degrees on man-made energy, technological solutions, and environmental control to achieve re-circulation and water/ambient temperatures. However, if a system is designed with energy conservation in mind, using alternative energy and a reduced number of pumps by letting the water flow downwards as much as possible, it can be highly energy efficient. While careful design can minimize the risk, aquaponics systems can have multiple 'single points of failure' where problems such as an electrical failure or a pipe blockage can lead to a complete loss of fish stock. maintenance is the issue in most of these circumstances a proper schedule of maintenance is a must for all aquaponic systems big or small commercial or hobby.
As existing hydroponic and aquaculture farming techniques form the basis for all aquaponics systems, the size, complexity, and types of foods grown in an aquaponics system can vary as much as any system found in either distinct farming discipline. This is just a basic overview of what It is for more information check out the forums at http://community.theaquaponicsource.com/
