Symptoms
- Chlorine level drops despite the salt system running
- Control panel shows a low salt or inspect cell warning
- Salt cell has visible white or gray buildup
Likely causes
- CommonScale buildup on the salt cell platesCalcium and mineral deposits coat the cell's plates and reduce chlorine production.
- CommonSalt level too low or too highSalt systems need salt within a specific range to generate chlorine properly.
- PossibleWater temperature too lowMost salt cells produce little to no chlorine below about 60°F.
- PossibleWorn out salt cell nearing end of its lifespanSalt cells typically last 3–7 years before needing replacement.
What to do
- Test the salt level with a test strip or the system's built-in sensor and adjust by adding or diluting as needed.
- Inspect the salt cell for visible scale buildup on the plates.
- Clean the cell using a manufacturer-approved cleaning solution (often a diluted acid wash) if scale is present, following safety instructions closely.
- Check the system's settings to confirm chlorine output percentage and pump run time are set appropriately for pool size.
- Note the water temperature, since chlorine production naturally slows or stops in cold water.
- If the cell is clean and salt/settings are correct but output remains low, the cell itself may be worn out and need replacement.
Tools and parts
- Salt test strips
- Cell cleaning stand or solution
Salt chlorinator cellSearch: “pool salt cell replacement”
Cell cleaning solutionSearch: “salt cell cleaning acid solution”
When to call a pro
A pool technician can test cell output directly and confirm whether replacement is needed versus a settings or salt level issue.
Safety
Use caution
Wear gloves and eye protection when handling acid-based cell cleaning solutions, and always add acid to water, never water to acid.