Feed water comprising an aqueous salt solution is supplied to an anode chamber and to a cathode chamber. The feed water is cathodically electrolyzed in the cathode chamber to produce alkaline electrolyzed water (catholyte) and is anodically electrolyzed in the anode chamber to produce electrolyzed water (anolyte) whose pH is modified. A portion of alkaline catholyte from the cathode chamber is recycled back to the feed water during continuous electrolysis to provide a blend of feed water and alkaline catholyte to the anode chamber to control pH of the anodically electrolyzed water therein to provide more stable bactericidal activity thereof over time.