How to Fix Cloudy Hot Tub Water

Cloudy water is usually caused by low sanitizer, high alkalinity, or dirty filters. Address each with our guides and calculators.

Low sanitizer

If chlorine (or bromine) is too low, bacteria and particles can multiply and cloud the water. Test and add chlorine to reach 3–5 ppm. Use our Hot Tub Chlorine Calculator. You may need to shock—see Hot Tub Shock Calculator. Run jets 15–20 minutes after adding.

High alkalinity

Alkalinity above 120 ppm can cause cloudiness and scaling. Add pH reducer (dry acid) per product instructions to lower alkalinity and pH. Re-test and keep alkalinity 80–120 ppm and pH 7.2–7.8. Use our Hot Tub pH Calculator for pH adjustments.

Dirty filters

Clogged or dirty filters can’t clear particles. Rinse or clean the filter according to your spa manual. In severe cases, replace the filter. After cleaning, run the pump and add sanitizer as needed.