Hydroponics, Aquaponics and Aeroponics.

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Hydroponics is a subset of hydro culture and is a method of growing plants using mineral nutrient solutions, in water, without soil. Terrestrial plants may be grown with their roots in the mineral nutrient solution only or in an inert medium, such as perlite, gravel, mineral wool, expanded clay pebbles or coconut husk. Researchers discovered in the 18th century that plants absorb essential mineral nutrients as inorganic ions in water. In natural conditions, soil acts as a mineral nutrient reservoir but the soil itself is not essential to plant growth. When the mineral nutrients in the soil dissolve in water, plant roots are able to absorb them. When the required mineral nutrients are introduced into a plant's water supply artificially, soil is no longer required for the plant to thrive. Almost any terrestrial plant will grow with hydroponics. Hydroponics is
also a standard technique in biology research and teaching.


History


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. Water culture became a popular research technique after that. In 1699, John Woodward published his water culture experiments with spearmint. He found that plants in less-pure
water sources grew better than plants in distilled water. By 1842, a list of nine elements believed to be essential to 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 soilless cultivation. Growth of terrestrial plants without soil in mineral nutrient solutions was called solution culture. It quickly became a standard research and teaching technique and is still widely used today. Solution culture is now considered a type of hydroponics where there is no inert medium.
In 1929, William Frederick Gericke of the University of California at Berkeley began publicly promoting that solution culture be used for agricultural crop production. He first termed it aquaculture but later found that aquaculture was already applied to culture of aquatic organisms. Gericke created a sensation by growing tomato vines
twenty-five feet high in his back yard in mineral nutrient solutions rather than soil. By analogy with the ancient Greek term for agriculture, geoponics, the science of cultivating the earth, Gericke coined the term hydroponics in 1937 (although he asserts that the term was suggested by W. A. Setchell, of the University of California) for the culture of plants in water (from the Greek hydro-, "water", and ponos, "labour"). Reports of Gericke's work and his claims that hydroponics would revolutionize plant agriculture prompted a huge number of requests for further information. Gericke refused to reveal his secrets claiming he had done the work at home on his own time. This refusal eventually resulted in his leaving the University of California. In 1940, he wrote the book, Complete Guide to Soilless Gardening.
Two other plant nutritionists at the University of California were asked to research Gericke's claims. Dennis R. Hoagland[5] and Daniel I. Arnon[6] wrote
a classic 1938 agricultural bulletin, The Water Culture Method for Growing Plants Without Soil,[7] debunking the exaggerated claims made about hydroponics. Hoagland and Arnon found that hydroponic crop yields were no better than crop yields with good-quality soils. Crop yields were ultimately limited by factors other than mineral nutrients, especially light. This research, however, overlooked the fact that hydroponics has other advantages including the fact that the roots of the plant have constant access to oxygen and that the plants have access to as much or as little water as they need. This is important as one of the most common errors when growing is over- and under- watering; and hydroponics prevents this from occurring as large amounts of water can be made available to the plant and any water not used, drained away, recirculated, or actively aerated, eliminating anoxic conditions, which drown root systems in soil. In soil, a grower needs to be very experienced to know exactly how much water to feed the plant. Too much and the plant will not be able to access oxygen; too little and the plant will lose the ability to transport nutrients, which are typically moved into the roots while in solution. These two researchers developed several formulas for mineral nutrient solutions, known as Hoagland solution. Modified Hoagland solutions
are still used today.
One of the early successes of hydroponics occurred on Wake Island, a rocky atoll in the Pacific Ocean used as a refueling stop for Pan American Airlines. Hydroponics was used there in the 1930s to grow vegetables for the passengers. Hydroponics was a necessity on Wake Island because there was no soil, and it was prohibitively expensive to airlift in fresh vegetables. In the 1960s, Allen Cooper of England developed the Nutrient film technique. The Land Pavilion at Walt Disney World's EPCOT Center opened in 1982 and prominently features a variety of hydroponic techniques. In recent decades, NASA has done extensive hydroponic research for
their Controlled Ecological Life Support System or CELSS. Hydroponics intended to take place on Mars are using LED lighting to grow in different color spectrum with much less heat.


Advantages


Some of the reasons why hydroponics is being adapted around the world for food production are the following:
•No soil is needed for hydroponics
•The water stays in the system and can be reused - thus, lower water
costs
•It is possible to control the nutrition levels in their entirety - thus,
lower nutrition costs
•No nutrition pollution is released into the environment because of the
controlled system
•Stable and high yields
•Pests and diseases are easier to get rid of than in soil because of the
container's mobility
•It is easier to harvest
•No pesticide damage
•Plants grow healthier
•It is better for consumption

Today, hydroponics is an established branch of agronomy. Progress has been rapid, and results obtained in various countries have proved it to be thoroughly practical and to have very definite advantages over conventional methods of horticulture. There are two chief merits of the soil-less cultivation of plants. First, hydroponics may potentially produce much higher crop yields. Also, hydroponics can be used in places where in-ground agriculture or gardening are not possible.


Disadvantages


Without soil as a buffer, any failure to the hydroponic system leads to rapid plant death. Other disadvantages include pathogen attacks such as damp-off due to Verticillium wilt caused by the high moisture levels associated with hydroponics and over watering of soil based plants. Also, many hydroponic plants require different fertilizers and containment systems.


Techniques


The two main types of hydroponics are solution culture and medium culture. Solution culture does not use a solid medium for the roots, just the nutrient solution. The three main types of solution cultures are static solution culture, continuous-flow solution culture and aeroponics. The medium culture method has a solid medium for the roots and is named for the type of medium, e.g., sand culture, gravel culture, or rockwool culture. There are two main variations for each medium, sub-irrigation and top irrigation. For all techniques, most hydroponic reservoirs are now built of plastic, but other materials have been used including concrete, glass, metal, vegetable solids, and wood. The containers should exclude light to prevent algae growth in the nutrient solution.

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I am planning on doing another how to for building a cheap and efficient indoor hydroponic system. Like last time I will take pictures of the materials used and of the construction. I will explain the process and pricing. So let me know what type of system you would like me to build.

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If you have not seen my last project, you can see it with the link below.

Cheap Hydroponic Project