Ion exchange rate of Ca2+ cations have been measured and the cationic form of zeolite A the use of which provided the shortest time of process has been selected. The exchange of monovalent Na+,NH4+, K+, and Li+ ions from the zeolite A skeleton on divalent ions of Ca2+ from the solution has been investigated. Experiments were carried out at static conditions for water temperature of 293 and 343 K and for various zeolite to water rations. As a criterion of exchange, i.e. the selection of the best cationic form of zeolite, tenfold decrease in water hardness from 10 to 1 degrees n, was assumed. Advantages of the use zeolite A as a component of washing powders have been shown and the possibillity of zeolite regeneration has been proved.