Why is my hot tub water cloudy?

Cloudiness is particles hanging in the water: skin oils, soap, organic matter, or minerals falling out of solution, all on Hot Spring's list of causes. Each cause in the table either adds particles or stops the filter and sanitizer from removing them. High pH is a double hit: Hot Spring says it clouds the water and lays scale, and Master Spas lists poor chlorine efficiency as another result.

1. Clean or swap the filter; it is the most common cause. See how to clean a hot tub filter.
2. Test and fix alkalinity, then pH.
3. Bring sanitizer up to your range and shock the water.
4. Run the jets with the cover open, then let the filter work for a few cycles.
5. Still cloudy: drain, clean the shell and refill, the last step in both makers' tables.

New water brings its own minerals and metals. Master Spas says to fill through a pre-filter and add a sequestering agent at every fill, then let it circulate before adding other chemicals. If your water is hard, calcium can cloud it as soon as it heats; see calcium hardness.

Better not. Master Spas' standard for good water is a clear view of the bottom, and cloudy water often means sanitizer is losing. Test it first; if chlorine and pH are off, fix them before anyone gets in.