Abstract: An improved method of controlling algal and bacterial pollution, as well as reducing the concentration of dissolved calcium, in a swimming pool, without the necessity of adding electrolytes thereto, involving the steps of:(a) conveying a stream of water from the swimming pool to an enclosed area and back to the pool;(b) providing a pair of spaced-apart electrodes in the enclosed area through which the water is to pass, the electrodes being chemically active and made from mixtures of silver and aluminum alloy containing from about 0.5 to about 5.