A system for and method of sanitizing water and waterway surfaces using ozone gas is disclosed wherein water is circulated from a water reservoir in a water ozonation loop means. Ozone is generated by an ozone generator and dispensed into the circulating water by an ozone feed means. In some embodiments the ozone is generated from gas in the water reservoir and dispensed into the water ozonation loop means at a venturi tube. A controller is provided for activating an ozonation cycle. In some embodiments, the ozonation cycle includes the actuation of a circulating water pump for a cycle interval, and the actuation of an ozone generator during an ozone generation interval, which is less than the cycle interval.
