Abstract: Water treatment involves delivering an instantaneous electric current to one or more pairs of activated electrodes immersed in the water, each of the pairs of electrodes comprising a sacrificial electrode operating predominantly as an anode and an inert electrode operating predominantly as a cathode. The sacrifical electrode, when as an anode, is able to provide dissolved ions to the water as current passes between the pairs of electrodes, to assist in treating the water. The polarity of the electrodes is periodically reversed to reduce electrode clogging. The amount of charge passed by the instantaneous electric current is indicative of the degree to which the water has been treated, and is used to control the treatment process.