Water is an excellent solvent and readily dissolves minerals it comes in contact with. As water moves through soil and rock, it dissolves very small amounts of minerals and holds them in solution. Water hardness varies from region to region, depending on the amount of minerals which dissolve in rainwater as it soaks through the ground. Water is harder in chalk or limestone areas than those with insoluble rock such as granite. Hardness is caused by compounds of calcium and magnesium, sometimes, other divalent and trivalent metallic elements, and by a variety of other metals. Calcium and magnesium dissolved in water are the two most common minerals that make water "hard." So the 'hardness' of water depends on the amount of calcium it contains - the higher the levels of calcium, the harder the water.
Water hardness is one of the most important chemical parameters when it comes to judging the quality of water. This doesn't affect the quality of the drinking, you can drink water with high hardness, and therefore there is no rule to establish what value should be present in the water from our taps. Actually, some people consider that hard drinking water generally contributes a small amount toward total calcium and magnesium human dietary needs. When hard water is heated, the presence of bicarbonate precipitates like calcium carbonates, which results in limescale crusts. Mineral deposits are formed by ionic reactions resulting in the formation of an insoluble precipitate. This precipitate, known as scale, coats the vessels in which the water is heated, producing the mineral deposits. As these deposits build up, however, they reduce the efficiency of heat transfer. Furthermore, scale can accumulate on the inside of appliances, such as dishwashers, and pipes. As scale builds up, water flow is impeded, and hence appliance parts and pipes must be replaced more often than if Ca2+ and Mg2+ ions were not present in the water. Limescale is harmless but it is advisable to clean kettles and keep hot water systems below 60°C to help keep build-up to a minimum.
We know calcium carbonate as lime often in colloquial language (think, for example in cleaning products that promise to eliminate limescale in toilets or shower screens, but usually these are rather the result reaction of calcium with soap). Yet it is not just a housekeeping issue, if the solid deposit occurs in industrial settings, it can lead to the occurrence of costly failures in boilers, cooling towers and other equipment. These limestone crusts can be eliminated causing chemical reaction reverse to the one explained above, that is, to form soluble calcium bicarbonate and again. This can be accomplished, for example, by adding an excess of carbon dioxide or a weak acid such as acetic acid (vinegar) or citric (lemon juice) acid. Many cleansing preparations for descaling are based, in fact, in a slightly acidic pH.
Grain and Water Hardness is usually expressed in grains per gallon (or gpg) as calcium carbonate equivalent. The number of total hardness a the parameter directly affects the size of the smoothing filter.
Effects of Hard Water However, the fact that no limited hardness in drinking water is set does not mean it has no detrimental effects in many domestic everyday processes such as mineral deposits on dishes and glassware; dry, itchy skin and scalp; unmanageable hair; extra work to remove soap curd on bathtubs and shower stalls, scale buildup in sinks, tubs, faucets and appliances; and high energy costs, possibly due to scale buildup in pipes and on appliances..
The term hardness was originally applied to waters that were hard to wash in, referring to the soap wasting properties of hard water. The harder the water is increased amount of detergent in each wash spend. Hardness prevents soap from lathering by causing the development of an insoluble curdy precipitate in the water. This is because soaps are alkali metal carboxylates derived from fatty acids with long carbon chains. Calcium reacts directly with the soap forming insoluble lumps. This can cause stiff, dingy laundry and high soap usage or need for fabric softeners. Minerals associated with hard water accumulate in clothing fibres, weakening and numbing color..
When watering plants, it is necessary to characterize the quality of irrigation water itself, the value of this parameter should be taken in consideration depending on the type of soil, because the effect of water can be positive or negative.
Water treatment can Improve Hardness Issues As previously explained, scale deposits from hardness build-up affects fixtures and appliances found throughout the entire home or business. For this reason, hardness is typically addressed with treatment of water for the whole house or building rather than just at a specific faucet. Water softeners and water filters assist two distinct services. It can be easy to confuse the two, or think there is a one device does all solution to your home water needs. The truth is they both serve unique purposes, and whether you need neither, one or both is determined by your local water supply..
By removing or almost completely eliminate these substances, fouling and clogging of pipes are avoided, saving costly repairs. It also makes more efficient water heaters reducing the consumption of gas or electricity. Also generate savings of soap for washing fabrics, dishes, etc. boilers and industrial level, sprinklers, pumps and piping systems, etc.