All about ORP / Redox

The ORP (Oxydo Reduction Potential) also known as REDOX represents the rate of disinfection of the water in your pool or spa. An ORP probe, found in particular in your ICOmeasures the electrical potential delivered by all chemical disinfectants. It is expressed in mV. The ORP measurement is more reliable than strips or DPD which measure a specific disinfectant level (chlorine) which is not always effective (see our video the different types of chlorine).

Vue sondes ICO - ORP, pH et conductivité. Sondes modifiables.

What is the difference between chlorine concentration measurement and ORP measurement?

ORP-REDOX gives direct information on disinfection whereas the amount of disinfectant must first be correlated with certain parameters (pH, amount of stabiliser, etc.) to be representative of the disinfection of the water. Chlorine disinfection is very sensitive and varies in
water conditions such as temperature. As mentioned in our article onthe impact of heat, l’efficacité du chlore diminue considérablement au-dessus de 28°C .

The impact of pH on chlorine :

ICO recommends a pH level of between 7 and 7.4 because the active chlorine content is best at these values (66%). In other words, it is more effective in disinfecting the water.

schema taux de pH chlore actif
Going from pH 7.4 to 7.8 lowers the amount of active chlorine by

To summarize : by measuring the ORP / Redox, ICO gives you an overview of the quality of
disinfection of your water unlike strips which give a partial view of the water balance.

schema comparatif mesure ORP / Redox et mesure du taux de désinfectant.

International standards recommend ORP / Redox readings between 650 and 750mV for optimal water disinfection at 25°C.