Knowledge Base

This is a sign of chemical damage. Chemical damage can occur when the cover is exposed to unbalanced water for an extended period or when the underside is subjected to harsh chemicals, such as very high sanitizer levels. It can also result from oxidation, which happens when you shock the hot tub and then close the cover too soon of if you use a ozonator. In that situation, the oxidation gases become trapped, allowing them to penetrate the cover and damage the underside.