Abstract: The method for managing the polarity-reversal frequency of at least one pair of electrodes in an electrochemical reactor for water electrolysis includes observing a fluctuation in the hydrogen potential (pH) of the water, while carrying out a comparison of the pH measured at a given moment with a previous measurement or a predetermined initial value. An amount of treatment agent is injected into the water to adjust the pH to around a defined set point. The polarity-reversal frequency of electrodes is calculated on the basis of the temperature of the water, the pH fluctuation and amount of agent injected. The method includes estimating the total alkali strength on the basis of the injected amount and the pH fluctuation, anticipating the fluctuations in the pH relative to the preceding estimations, and readjusting complete alkalinity titration estimate and calculation of the polarity-reversal frequency.