Robarb 20750A Spa Specialties Suds-X Defoamer for Spas and Hot Tubs, 1-Pint Foam can be caused by a high concentration of chemicals due to evaporation and build up of body oils, cosmetics and other contaminants It is recommended that you occasionally add Suds-X to reduce excessive foaming due to body oils, shampoos or soaps Suppresses suds caused by soap, lotion or oil residue build-up