This application allows you to quickly obtain the active chlorine content (HOCl), for water without stabilizer (cyanuric acid), depending on:
– free chlorine content: measured on site at DPD1,
– pH and water temperature measured on site,
– the ionic strength of water. That is to say its mineralization defined in three types:
– lightly or moderately mineralized water (IS < 0.05 or dry residue < 1500 mg/l),
– highly mineralized water (IS > 0.05 or dry residue > 1500 mg/l),

The ionic strength can be evaluated with good precision with the dry residue. This parameter often appears on the laboratory analysis report.
If you have this result, it is recommended to enter it in the corresponding box to improve the accuracy of the active chlorine calculation.

The more acidic the pH (< 7), the greater the fraction of active chlorine for the same value of free chlorine. Active free chlorine is the most germicidal part of free chlorine.

In France, regulations require swimming pools accessible to the public:
In the absence of stabilizer: 0.4mg/l < active chlorine < 1.4mg/l.
In the presence of stabilizer: there is no active chlorine: free chlorine > 2mg/l.