NetSpa spa water has a strong chemical or musty odor despite normal operation.

Safety first: Do not use the spa until water chemistry is balanced.

• Test water: Use NetSpa-recommended test strips to check sanitizer, pH, and alkalinity levels.
• Shock the spa: Add a non-chlorine or chlorine shock treatment according to spa volume and product instructions.
• Increase filtration: Extend the daily filtration cycle to improve water turnover.
• Clean/replace filter: Rinse or replace the NetSpa filter cartridge to remove trapped contaminants.

Persistent odor may require draining, cleaning the spa shell, and refilling with fresh water, then maintaining proper chemical balance.