An automatic, self-regulating method of water treatment for use in water circulating towers in which water is evaporated, and make up water is added, with components which synergistically function to cut chemical, energy, water, corrosion, pollution, and maintenance costs, by passing the water through a Water Conditioning unit to prevent adhering evaporation scale deposits along with their content of concentrated biofouling nutrients from forming on the flooded surfaces of the tower and its associated water flow circuit, adding a trace level of iodine to the input make-up water to enhance the further disinfection of nutrient-deprived surfaces from any residual biofllm and chance pathogen contaminations, and adding a trace level addition of zinc ions in the water such as by an assured treatment feeder to the input make-up flow for inhibiting residual iodine-resistant algal and bacterial organisms of hazard for restoring bionutrient tower conditions, such as within sun-lit environments, and apparatus for carrying out the foregoing method.