Commercial pools target 1.0 – 3.0 ppm. Chlorine sanitizes the water and kills bacteria. Tested with a DPD or ORP sensor.
Commercial pools target 7.2 – 7.6. pH controls chlorine effectiveness and swimmers' comfort. Below 7.2 causes eye/skin irritation; above 7.6 reduces chlorine potency.
Commercial pools target 80 – 120 ppm. Alkalinity buffers pH against rapid swings. Low alkalinity causes corrosion; high makes pH hard to adjust.
Commercial pools target 30 – 50 ppm (indoor: 0). CYA stabilizes chlorine against UV degradation. High CYA locks chlorine — require higher free chlorine to maintain efficacy.
Calculate precise dosing · Chlorine · pH · Alkalinity · CYA