Water is a vital requirement for human life. Humans need it for various purposes ranging from drinking water, washing, bathing and others. Water sources include surface water, rainwater, well water (ground water). Well water is more widely used to meet these needs because it is better than the quality of water resources in a manner lain.Pengolahan well water demineralization already done diindustri-chemical industries but is still rare among the general public. Common processing method is simple water filtration with gravel, fibers and sand. The processing method is less efficient for water with a little Ca content, so that other methods are needed in the well water treatment is the method of demineralized water so produced has a low Ca content. The basic principle of the method is the exchange demineralization of mineral ions in water such as Ca using ion excange resins.
Keywords: water demineralization, hardness, ion exchang
