Troubleshooting guide
Cloudy or smelly hot tub water
Cloudy water is almost always about filtration and sanitizer, not equipment. Here's what manufacturers and the CDC say to check.
Check the numbers first
Test with fresh test strips or a test kit. The CDC recommends these levels for hot tubs:
- Chlorine: at least 3 ppm
- Bromine: 4 to 8 ppm
- pH: 7.0 to 7.8
Your spa's manufacturer may give its own targets (and some sanitizer systems use different levels), so follow your owner's manual where it differs. Hot Spring, for example, says not to use the spa until free chlorine drops below 5 ppm after shocking.
What causes it (manufacturer table)
| Problem | Likely causes | What to do |
|---|---|---|
| Cloudy water | Dirty filters, excess oils, low sanitizer, suspended particles, old water | Clean filters, shock, add sanitizer, adjust pH / alkalinity, run the jets, or drain and refill |
| Water odor | Excess organics, low sanitizer, low pH | Shock, add sanitizer, adjust pH |
| Chlorine smell | Chloramines too high, low pH | Shock, adjust pH |
| Musty smell | Bacteria or algae growth | Shock; if it persists, drain, clean and refill |
| Scum ring | Oils and dirt | Wipe it off; if severe, drain, clean and refill |
Source: Hot Spring's spa water maintenance troubleshooting guide. The CDC also notes that a properly chlorinated hot tub has little odor, and a strong chemical smell points to a problem.
Foam and old water
Hot Spring explains that soap from bathers and clothing builds up in the water and isn't removed by sanitizer. Foam inhibitors hide it but don't remove it, and eventually the water needs draining and refilling. Its manual says water typically lasts about four months depending on use. Balboa controls can also show a "change the water" reminder.
When it's not the water
If the water won't clear even with good numbers and a clean filter, the circulation may not be running long enough, the ozonator may not be working, or a pump may not be moving water properly. A tech on video can check filtration settings and equipment with you.
Common questions
Why is my hot tub water cloudy after shocking?
Shock can temporarily cloud water while it breaks down oils and organics. Run the jets with the cover open, make sure the filter is clean, and retest pH and sanitizer. If it stays cloudy for days, the water may be old and need a drain and refill.
What chlorine level should a hot tub have?
The CDC recommends at least 3 ppm chlorine (or 4 to 8 ppm bromine) and a pH between 7.0 and 7.8 for hot tubs. Follow your spa manufacturer's guidance if it's different.
How often should I drain my hot tub?
It depends on use. Hot Spring says water typically lasts about four months before soap build-up makes a drain and refill necessary. Check your owner's manual for your model.
Related guides
Safe hot tub temperature
104°F is the ceiling. Why, and who should go lower.
Read the guideWeak jets or pump not working
Weak, surging or no jets: water level, filters and air first.
Read the guideAirlock after a refill
Just drained and refilled, and now no jets or no heat? Prime the pumps.
Read the guideWinterizing and freeze protection
Keep it running, or drain and winterize it properly. No car antifreeze, ever.
Read the guideSources
- CDC Healthy Swimming: What you can do to stay healthy in hot tubs (temperature, chlorine, bromine and pH)
- Hot Spring Spas (Watkins Wellness), Hot Spot collection SX/TX owner's manual: GFCI and high-limit checks, priming, drain & refill, winterizing and troubleshooting tables
- Balboa Water Group, Spa Touch 3 user guide: panel messages, flow-related checks and reminders
Brand names belong to their owners. Hot Tub Helpline isn't affiliated with or endorsed by any manufacturer. Steps and codes vary by model and year, so always check your own owner's manual.