Abstract: An electrolytic water sterilization system comprises a rate detecting cell, an oxidation cell and a silvering cell through which the water flows. The rate detecting cell is fitted with two electrodes and is partly filled with non-conducting particles whose density is greater than water. The upwards flow of water expands the bed of particles providing greater free area between the electrodes. The electrical resistance between the electrodes is reduced accordingly. The current to the electrodes of the oxidation cell and the silvering cell is controlled by the detected flow rate. Preferably, the rate detecting cell, the oxidation cell and the silvering cell with their corresponding electrodes are combined in one single cell.