Foaming spa water is a result of too many oils in the water for the sanitizer to handle. Sanitizers alone have a difficult time breaking down lotions, make up and other body oils. The result is foamy spa water. A product called foam out can be used as a temporary solution. If foamy spa water becomes a chronic problem, use a product called Natural Clear as part of your weekly routine. Natural Clear and products like it digest oils thus removing them from the water.