Water used in dishwashers in various catering establishments must satisfy a number of requirements. In order to comply with the requirements are used filters and water softeners. Thus, special filters purify water from various contaminants (sediments, chemical compounds, microorganisms, dissolved solids, etc.), which have been accumulated while moving through water supply and may adversely affect the operation of the equipment. For water treatment are applied different filters: mechanical appliances cleansing stream from mud and debris, carbon filters, removing chemicals and volatile organic compounds, etc. Hard water is not less harmful to the equipment, because it promotes to production of lime scale. For regulation of the water balance - use water softeners. Inside water softeners water is passed through a sodium solution, and as a result increasing water hardness salts of magnesium and calcium are exchanged for sodium ions and stay inside the softener. Some dishwashers have an internal softener that has a special opening to fill up with special or coarse salt, which also helps to reduce water hardness level and bring it back to normal.