What Are the Recommended Chlorine Levels for Commercial Pools?

Free available chlorine (FAC), or the residual amount of unreacted chlorine contained in the water, should be maintained between 1.0 and 3.0 ppm or as per local regulations. Poolside by CGT recommends maintaining proper chlorine levels to balance sanitation and long-term membrane durability. If the free chlorine drifts too low, algal and bacterial growth may occur and prolonged exposure could stain the membrane. Pool surfaces are also susceptible to bleaching or loss of color if exposed to high concentrations of FAC. Should recommended concentrations be adhered to, slight bleaching and fading can occur gradually over a period of several years. Increase in Chlorine Levels in Special Circumstances Outside of normal operation parameters, there may be reasons to superchlorinate your pool. Direct contact of the membrane with trichloro-iso-cyanurate stabilized chlorine can result in an almost total bleaching of color in a time as short as 6 to 24 hours. The reasons are a high available chlorine content of 90%, the low solubility or rate of dissipation of the granules or pucks, and extremely low pH produced in the contact areas. The immediate effects of other types of chlorine such as dichlorisocyanurate, calcium hypochlorite, sodium hypochlorite (liquid chlorine) is not as rapid and severe if they are not mixed with other chemicals during or shortly after addition to the pool. Solutions of the above chlorines can be applied directly to the membrane for several hours to bleach stains without adversely affecting the membrane. If the concentrations of the above FAC are allowed to remain higher than the recommended levels of 5.0 ppm for superchlorination or 10.0 ppm for shocking, or for long periods of time, gradual bleaching of most membranes will occur. If the concentration level exceeds 10.0 ppm, be aware of the potential for negative effects of the membrane.

Free available chlorine (FAC) should typically remain between 1.0 and 3.0 ppm to maintain sanitation, prevent algae growth, and protect the integrity of the pool membrane.