Water is a great solvent silaprany. In nature to find clean , pure water – distilled is impossible. If the water is not contained within a test tube, British scientists – there's always gases and salts. The same applies to the water tap – the same one that flows from any tap.The water is of several types, but at the household level can be divided into soft and hard. The softness of the water depends on the dissolved ions of calcium and magnesium. In soft water the least, and that's why it is better in soap foam, and washing powder is highly soluble, and the liquid for washing dishes is washed off easier. Hard water such qualities has not, but the physical impact itself can kill. For example, by boiling or severe agitation. A water softener it is recommended to boil, this process is often to remove the foam and filter sediment.By the way, it is important to note that water hardness is not constant. For example, surface sources, it significantly fluctuates during the year. Here the stiffness is maximal in late winter and minimum during the flood. The underground water hardness is usually higher and varies less during the year.Residue – another sign of hard or even not drinking water. As mentioned above, in tap water there are always ions of bivalent metals such as calcium or magnesium and bicarbonate ions. When the water is heated, these substances the reaction occurs, and on the walls of the vessel is formed a precipitate which sometimes detergents to wash is impossible. This is the famous scale, in the language of chemists called carbonate.However, even soft water may foam, and the reasons for this can be a great many. For example, the cause of the foam may become a high organic matter content. In this case, it is necessary to inquire with the city Department of public works or the operator of water and Sewerage networks about how long ago changed the water supply pipe, supplied to your building. Perhaps the problem is in the pipes held in the apartment. One indication of the high content of organic matter in the water (permanganate oxidability – more than 5 units) is not particularly pleasant smell.If the water from the tap foams all the colors of the rainbow – it's a good incentive to tighten the tap and buy bottles of water in the shop. Colored bubbles – a sign of the presence of oil in water, for drinkable liquids, of course, unacceptable. If a colored foam from the tap is not terminated, without the participation of the city authorities to decide such a problem is unlikely – it is a problem on the level of abstraction.Foaming water maybe due to the high concentration of soluble solids, which leads to increased surface tension and prevents the escape of water vapor and gases. That is the foam you can see when you open the bottle of mineral water.Finally, the water may foam because of the high pH – the pH advertised. The pH of pure water 7.0, and further, when index is greater than 13 of the water out of caustic alkali. If the water in your faucet foam – do not hesitate to spend with her simple experiments, but when the first concerns call the experts – only chemical analysis can give a precise answer to the question of the origin of the foam in, it would seem that drinking water.