Jandy AquaPure Cell Cleaning: Code 125 Acid Wash Procedure

Inspection Before Cleaning

1. Turn off the pool pump and release system pressure by opening the air relief valve on the filter.
2. Remove the flow/temp/salinity sensor from the 3rd port by unscrewing the coupling nut. Pull straight out.
3. Remove the cell from the plumbing by unscrewing both coupling nuts on the flow ports.
4. Look through the cell. You are looking for white crusty deposits (calcium carbonate scale) on the electrode plates and any debris between the plates.
5. A small amount of scale is normal. If the plates are mostly clear, the cell probably does not need cleaning.

Acid Wash Cleaning Procedure

1. First try a high-pressure jet of water from a garden hose. This may dislodge loose scale and debris without needing acid.
2. If the hose does not adequately clean the cell, proceed with acid cleaning.
3. Plug the two adjacent ports on the cell. Do not use the sensor as a plug.
4. In a plastic bucket, mix 2 quarts of tap water first, then add 1 pint of muriatic acid.
5. Pour the acid/water mixture into the cell through the open port.
6. Watch for foaming. Vigorous foaming means calcium carbonate is dissolving.
7. If no foaming occurs, the cell does not have significant scale. Stop and proceed to rinsing.
8. Allow the cell to soak until foaming stops, but never more than 30 minutes.
9. Pour out the solution carefully. Rinse thoroughly with clean tap water.
10. Inspect the plates. If deposits remain, repeat the procedure with fresh solution.
11. Rinse again and reinstall the cell with fresh O-rings if needed.

Cleaning the Flow/Temp/Salinity Sensor

While the cell is out, clean the sensor too. Scale on the sensor contacts causes inaccurate salinity readings.

1. Use a mildly abrasive green fiber household cleaning pad (Scotch-Brite type).
2. Gently scrub the sensor contacts until clean and bright.
3. Rinse thoroughly with clean tap water.
4. After reinstalling, turn power off and back on to recalibrate the sensor. This is required any time the sensor is disconnected.

When to Clean vs. Replace

• Clean if you see scale and acid wash produces vigorous foaming.
• Replace if acid wash produces no foaming but code 125 persists. The plates are worn out.
• Replace if recurring low-current codes persist after thorough cleaning. The cell has likely reached end of life.
• Replace if you are cleaning more than every 2 months despite balanced water chemistry.

Preventing Scale Buildup

• Maintain pH between 7.4 and 7.6. High pH is the primary driver of calcium scale.
• Keep calcium hardness between 175 and 400 ppm.
• Maintain total alkalinity between 80 and 120 ppm.
• Use stabilizer (CYA) at 50-75 ppm.
• Never use dry acid to adjust pH in arid areas with excessive evaporation.
• Inspect the cell monthly initially, then extend to biannual if no scale is found.