Water has a strong chemical or musty odor despite normal sanitizer levels.

Safety: Handle chemicals with gloves and eye protection. Follow all label directions.

• Step 1 – Shock treatment: Perform a high-level chlorine or non-chlorine shock according to your Catalina spa chemical guidelines. Run all pumps with air controls open.
• Step 2 – Clean filters: Remove filters and soak them in a filter cleaner solution, then rinse thoroughly. Replace if more than 1–2 years old.
• Step 3 – Plumbing purge: Use a spa plumbing purge product to remove biofilm from internal lines. Run pumps as directed, then drain the spa completely.
• Step 4 – Refill and balance: Refill with fresh water, balance pH and alkalinity, and re-establish sanitizer levels.