Abstract: An apparatus and method for electrolytically treating water which includes one or more reactors. Each reactor has a liquid containing vessel and one or more pairs of electrodes. The electrodes are suitable for a continuous anodic or cathodic operation for treating water. A power source for each reactor provides voltage and current to the electrodes. A controller maintains the voltage and current provided to the electrodes. The duration of each voltage polarity applied to each electrode is substantially the same. The polarity of the voltage to the electrodes is periodically reversed during which there is a period of zero voltage applied to the electrodes between a first polarity and a second polarity. The period of zero voltage results in a substantial reduction of back e.m.f. of the reactor which enhances the service life and efficacy of the electrodes.