Understanding ORP Probe Issues: 

The ORP (oxidation-reduction potential) probe's effectiveness can be compromised by substances in your pool, affecting its ability to accurately measure the oxidizing nature of the water. Common culprits include:


  • Biofilms: Micro-organism layers that adhere to surfaces. Clean by gently rubbing the ORP probe with a cotton bud soaked in 70° alcohol or isopropyl alcohol, then rinse with tap water.
  • Calcium Deposits: Visible lime film or aggregates. Remove by soaking the probe in half water, and half food-grade vinegar solution for about 5 minutes, then clean thoroughly.
  • Oils and Greases: Residues from sunscreens and creams. Eliminate using a cotton bud soaked in 70° alcohol or isopropyl alcohol, rubbing the probe gently, followed by a tap water rinse.
  • Hydrogen (H2) Production: Common in pools with salt chlorine generators, leading to low ORP readings. This does not harm the probe but affects measurement accuracy.

Solution for Hydrogen Interference:

If you're using a salt chlorine generator, the platinum reactivity with hydrogen might lower ORP values, misrepresenting free chlorine levels. For a more accurate measurement, consider upgrading to our 4-in-1 sensor with a gold reactive surface by contacting your reseller.

Note: Never use acetone for cleaning the probe.


If you have any questions about this topic, please get in touch with your pool specialist.