FIELD: electrochemical treatment of water for reduction of its hardness. SUBSTANCE: method consists in performing electrolysis of water being treated between anode and cathode by connecting with positive and negative terminals of current generator; each of them consists of at least one electrode. Fine and porous coat is formed on cathode; this coat consists at least partially of calcium carbonate. Simultaneously, electrolysis of water is performed and gas flow through porous holes of cathode is formed so that crystals consisting at least partially of sodium carbonate which are formed on above- mentioned coat should be separated from it under action of gas flow. Plant proposed for realization of this method has plating bath provided with anode and cathode. Cathode has a coat formed by porous calcium carbonate and units for passage of gas flow. Ratio of total surface of cathode to anode ranges from 10 to 20. EFFECT: complete or partial softening of water; enhanced economical efficiency and operational reliability. 18 cl, 7 dwg
