VISOCOLOR® ECO Swimming pool • Colorimetric determination of chlorine and pH-value • Free chlorine reacts with N,N-diethyl-1,4-phenylene diamine (DPD) to form a red-violet dye. • The pH value is determined with phenol red as indicator. • For test kits for the determination of chlorine alone see VISOCOLOR® Chlorine. Type: colorimetric test kit Range: < 0.1 · 0.1 · 0.2 · 0.3 · 0.4 · 0.6 · 0.9 · 1.2 · 2.0 mg/L Cl2 pH 6.9 · 7.2 · 7.4 · 7.6 · 7.8 · 8.2 Sufficient for: 150 determinations Shelf life at least: 1.5 years Sea water suitability: yes Detectable with PF-12: no • Chlorination of water in swimming pools with chlorine or chlorine compounds takes place within certain limits. • One distinguishes between free chlorine and bound chlorine (chloroamines); the sum of both is called total chlorine. • The content of free chlorine should be between 0.3 and 0.6 mg/L. • Chlorination alters the pH value of the swimming pool water. • The ideal pH value is pH 7.4. • This prevents formation of malodorous pollutants and irritants to the mucous membrane and prevents damage to the water treatment system.