The second edition manual is the basic text of the PHTA® Professional Pool & Spa Operator Course, which provides training and certification of commercial swimming pool & spa managers, operators, engineers, service company professionals, and facility owners. The manual is the basis of this certification / licensure-level course. It has been developed by the industry for the industry. The Association of Pool & Spa Professionals (PHTA®) is an international trade association of more than 3500 companies with some 150,000 member employees in the swimming pool, spa, and hot tub industry – including manufacturers, manufacturer agents, distributors, builders, renovators, retail stores, and service companies.