Biofouling and scale control in conductive aqueous systems is effected on metal, preferably valve metal such as titanium, surfaces on which such fouling normally occurs by applying thereto a stable electrocatalytic coating, anodically polarizing said valve metal coating such that essentially only oxygen is evolved at the surface thereof, preferably at a rate of at least about 4.66 millimoles per square meter per hour without evolution of any chlorine. Periodic current reversal is effected to forestall biofouling upon any cathode utilized in implementing the instant invention.