Bubbles and some foam are normal in spas or hot tubs when in use, but it’s not uncommon for hot tub owners to experience excess foaming in their spa. Though excess spa foam may be unsightly, it can also be evidence of a more serious problem.

When your spa has excess foam, the water may appear milky-white or frothy. Excess foam can be caused by unbalanced water, soaps, detergents and other contaminants that soakers introduce into the spa. Learn more about the specific causes and how to prevent and treat of excess spa foam.


Unbalanced Water

Low Total Hardness levels can cause foam to appear in your hot tub. Test and balance your spa water regularly. Pay close attention to your Total Hardness level. Always maintain Total Hardness between 175-275 ppm. 


Soaker Contaminants

Contaminants can build up in your spa water over time. Cosmetics, lotions, fragrances and oils that do not dissolve in water can cause your hot tub water to foam. To help prevent or reduce foam, rinse off before using your spa and apply a shock treatment specifically designed for use in spas and hot tubs weekly to help destroy organic contaminants. 


Cleaners and Detergents

Household cleaning products are not meant to be used with hot tubs and can cause excess film to build up on the walls and surfaces of your spa. This build up can cause spa water to foam. Do not use household cleaners or detergents on your hot tub.



Most algaecides foam and are not recommended for use with hot tubs. If an algaecide has been applied to spa water, it may take up to two weeks for the foam to dissipate. You may also consider draining your spa to remove any lingering presence of the algaecide.



If the source of your spa foam is unknown or to visibly reduce foam quickly, use an antifoam product design for use in hot tubs to eliminate and prevent foam.