Why Is My Hot Tub Cloudy? 7 Causes and Fixes
Cloudy hot tub water is one of the most common problems owners run into. The good news is that it almost always comes down to a handful of causes, and you can usually fix it in a day. Work through this list in order, starting with a fresh test.
1. Low sanitizer
If chlorine or bromine drops too low, bacteria and organic matter build up and the water turns hazy. Test with a test strip. A common target for home tubs is about 3 to 5 ppm free chlorine or 4 to 6 ppm bromine, but follow your spa maker's range. Top up with chlorine or bromine.
2. High pH or alkalinity
When pH or total alkalinity runs high, minerals can come out of solution and cloud the water, and sanitizer works poorly. Bring alkalinity into about 80 to 120 ppm first, then pH into about 7.2 to 7.8. A pH reducer like Spa Down lowers both. Full steps: how to balance pH and alkalinity.
3. A dirty or worn filter
A clogged filter can't trap the fine particles that make water look milky. Rinse the cartridge every week or two, deep clean it every month or so with a cartridge filter cleaner, and replace it when the pleats are worn or it won't come clean. Shop filter care, or follow our filter cleaning steps.
4. Oils, lotions and soap
Body oils, sunscreen, hair products and detergent left in swimsuits all add up. Shock the tub (here's how), and try oil absorbing sponges in the filter area to soak up scum. If you also see foam, a defoamer like Foam Down knocks it down while you fix the cause. More in how to get rid of hot tub foam.
5. Not enough shock
Without a weekly shock, waste builds up faster than your sanitizer can handle it. Shock once a week and after heavy use with a product from our shock collection.
6. Hard water or high calcium
High calcium can cloud the water and leave scale on the shell and jets. Many hot tub makers suggest about 150 to 250 ppm calcium hardness. A stain and scale product helps keep minerals in solution; see clarifiers, stain and scale control.
7. Old water
Over time dissolved solids build up until no amount of chemicals will keep the water sparkling. If it's been three to four months, it may be time to drain and refill.
Quick fix checklist
- Test the water.
- Balance alkalinity, then pH.
- Clean or replace the filter.
- Shock and run the jets with the cover off.
- Add a clarifier if the haze is still there after 24 hours.
- Still cloudy after a few days? Drain and refill.
Safety first: always follow the directions on the product label and your hot tub maker's manual. Add chemicals to the water one at a time, never mix chemicals together, and store them dry, cool and out of reach of kids and pets. Questions? Send us a message.
