Spa water has a persistent musty or moldy odor despite chemical treatment.

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

• Shock the spa: Add a non-chlorine or chlorine shock product according to Evolution Spas water care guidelines.
• Clean or replace filter: Remove the filter cartridge, soak in a filter cleaner solution, and rinse thoroughly. Replace if older than 1–2 years.
• Run jets: Operate all pumps and jets with air controls open for at least 30 minutes to circulate sanitizer through all lines.
• Drain and refill: If odor persists, perform a plumbing line flush with a spa purge product, then drain, clean the shell, and refill with fresh water.

Maintain proper sanitizer and pH levels to prevent recurrence.