Probe Care and Controller Calibration

Probe Care and Controller Calibration

If you operate a pool or spa, hopefully you enjoy the benefits of an automated chemical controller. For readers who are unfamiliar with chemical controllers, I cover the advantages of automation in my post "Automation". In that post I note that automated controllers constantly monitor swimming water and adjust chemical feeders accordingly. I see this as a huge time saving benefit to busy pool owners, operators and managers. While automation removes the constant task of feeder adjustment, maintaining proper pH and disinfectant levels still requires human involvement. To enable a chemical controller to properly maintain the desired pH and disinfectant levels, you should understand and employ probe cleaning and controller calibration. Cleaning a system's probes and calibrating its controller will keep your automated system running smoothly and will result in less hassle for you.

Before a person delves into probe cleaning and controller calibration, they should monitor their water. The 24/7 monitoring accomplished by the probes does not remove a pool owner or operator's responsibility to test their water's pH and disinfectant levels. This is especially true at public facilities because local codes set the maximum times allowed between tests. Since my company offers Pittsburgh pool services, I am familiar with the regulations set by the Allegheny Health Department. In Allegheny County, pool operators must monitor chemical quality every two hours for outdoor facilities and every six hours for indoor facilities when the pool or spa is open. The information gathered by your chemical tests will guide your probe cleaning and controller calibration efforts.

If your tests align with the desired set points of your controller, no cleaning or calibration is needed at this time. Continue with regular testing and note any changes. Over time a system's probes will get dirty or "foul". The time it takes for probes to foul varies from pool to pool. Materials, often invisible to the human eye, collecting on the probes surface cause the fouling. Components in the water contributing to dirtying probes include minerals, organics, body oils, suntan lotions, cosmetics, and cynuaric acid.

Signs that your pool's probes are dirty include increasingly slower response to sanitizer level changes and low or inaccurate readings displayed on the controller. Manufactures recognize that probes get dirty and include instructions on cleaning in their manuals. Generally these instructions involve:

  1. Turn off the pool pump

  2. Turn off power to the controller

  3. Remove the probes from the flow chamber

  4. Gently clean the probes with a soft brush and mild solution of water and acid or detergent

  5. Re-install the probes and turn on power to the pump and controller

After cleaning your systems probes, you should test the water and note the reading. Based on your reading, you should follow the controller’s instructions for calibrating the controller's pH and ORP readings.

While the process of cleaning a system's probes and calibrating its controller may seem involved and tedious, bear in mind the work will produce great results. Thirty minutes dedicated to probe cleaning and controller calibration can save you hours of time adjusting your feeders over the course of a season.

If you would like more information regarding probe care and controller operation, please feel free to reach out to Allegheny Pool Services Co. We offer both of these services. More information is available at our homepage. I also cover more information about feeder automation in my post "Automation". I hope you found this post helpful.

Thanks for reading,

Tim Johnson