pH level, or alkalinity, of water depends on concentration of calcium, magnesium, potassium and sodium carbonates and bicarbonates in the water – the higher is the content of these minerals in the water, the higher is the pH level. In nature, a pH level of fresh water generally varies from 6.0 to 7.5. Of course, there are also waters with a lower pH level, for example, marsh waters. In addition, there are several sources or underground waters with a pH level of 9.0 or above. Such waters can be considered alkaline. Unfortunately, there are few sites in the world where extraction of such alkaline water is enabled in natural conditions. In Europe, only about 20 alkaline water sources are known. In the Baltic countries, there is no known source of water with a pH level exceeding 9.0. At the same time, the fact that the pH level of water is above 9.0 does not mean that this water is fine, since it is virtually impossible to find perfectly balanced water in nature. Normally, there is something in the water that is either in excess or deficiency. For example, water can have a pH level of 9.3 and at the same time contain a variety of harmful mineral impurities (fluorine, ammonium, sulphur, excessively high salt concentration, etc.) Water flows through the depths of the earth and imbibes all the minerals and trace elements through which it runs. Natural water can also have a too high degree of mineralization, meaning that it has a too high concentration of dissolved minerals and trace elements, which is also bad for our organism.