pH was introduced by a Danish biochemist named Soren Peter Lauritz Sorensen in 1909 to measure the acidity of water for brewing beer. The letters pH is short for "potential Hydrogen."
pH is an index of Hydrogen's chemical activity in a solution and express the degree of acidity of a substance using a Log Scale Unit of Measure. pH level will range from 1 to 2 for strong acids, 7 for neutral solutions such as pure water and up 11 and higher for very strong bases like lye.
pH scale goes from 0 to 14 with seven being the neutral zone. Anything above is base or below is acidic with 0 being the most acidic and 14 the most base. Pure water is approximately a pH of 7 or neutral.
Importance of pH
Understanding the pH level of a solution is very useful in many industries. Chemistry and biochemistry requires a clear understanding of pH levels for the production of products such as nylon and other fibers. In plants, however, the correct level of pH aids in proper nutrient absorbtion. Each plant species has a particular pH range that it will thrive in. Should the pH fall out of range the nutrients in your media will become "locked-up" preventing plants from absorbing them.
In soil applications the pH can be thrown out of balance when inorganic fertilizers are used. Organic fertilizers typically do not make soil acidic and improve its fertility. The ideal pH level of a media can aid in the growth of microorganisms that convert nitrogen into a form that plants can use.
pH values above 7.5 cause iron, manganese, copper, zinc and boron ions to be less available to plants. Values below 6 cause the solubility of phosphoric acid, calcium and magnesium to decrease and become unavailable to plants. pH values between 3 and 5 and the ideal temperature, typically above 26 degrees Celcius will promote the development of fungal diseases.
Testing pH level
Gardner's can easily test a solution pH level using a pH test meter.
Controlling pH level
pH levels can easily be controlled using pH adjusters found at any hydroponics supply store. pH adjusters are usually referred to as pH Up for a higher level or pH Down to acidify nutrient solution.
This article courtesy of www.hydroponicsearch.com
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