When using organic chlorine products (trichlorisocyanuric acid and sodium dichlorisocyanurate), the so-called “isocyanuric acid” creates the carrier for chlorine. While the advantage of organic chlorine products clearly lies in the higher portion of active chlorine (up to 90%), the isocyanuric acid carrier substance can limit the speed at which the chlorine can kill off the bacteria when the concentration in water is high (>50 mg/l). It is thus recommended that one measure the cyanuric acid just as regularly as the chlorine content of the pool, in order not to counteract this fact by adding more chlorine (thus leading to higher isocyanuric acid being added).