Oxidizers (chlorine and bromine) sanitize pool water by releasing “free chlorine” to destroy bacteria. They also destroy organic matter to give the water a sparkling clean appearance. Oxidizer usage is affected by water temperature, pH, swimmer load, sunlight, rain and wind-blown debris. It is extremely important that the chlorine residual be continuously maintained at an effective level to ensure control over harmful bacteria. Daily testing for chlorine residual and pH should be common practice to maintain 1-3 ppm (mg/l) free available chlorine residual and a pH range of 7.2-7.6 in the water. Free Available Chlorine (FAC) is chlorine that has not reacted (combined) with bacteria or other organics (pollutants) and, therefore, is the level of active chlorine available to attack new organisms as they develop or are introduced into the pool water.
Algae Growth Prevention
Algae are persistent forms of microscopic plant life that are found almost everywhere. Their spores are in the atmosphere and are constantly being introduced to the pool water. In chlorine treated pools, algae growth can be prevented by maintaining a proper chlorine residual (1-3 ppm (mg/l) FAC) and using a quaternary algaecide. The use of a quaternary algaecide will not only help to control algal bloom but will lower the pool water’s chlorine demand, thereby lowering the amount of chlorine needed to establish the 1-3 ppm (mg/l) FAC sanitization residual. A typical initial application for quaternary algaecides is 2 ppm (mg/l) active. Weekly or bi-weekly maintenance doses should be approximately 0.5 ppm (mg/l) active quaternary.
Biguanide sanitizers are not effective algaecides. For this reason, a separate algaecide is required to maintain control of algal growth in pools. Biguanides are not compatible with chlorine, bromine, copper/silver ionizers and copper algaecides. Therefore, in order to control algae in biguanide treated pools, one must use a quaternary algaecide. The typical application of a quaternary algaecide in a biguanide pool is the same as in a chlorinated pool.
EPA Registered Swimming Pool Algaecides
Stepan currently has the following EPA registered Swimming Pool Algaecides based on our BTC® 2125M, BTC 776 and BTC 8358 quaternaries available for subregistration.
1839-89 5% BTC 776 Swimming Pool Algaecide
1839-87 10% BTC 776 Swimming Pool Algaecide
1839-141 50% BTC 776 Swimming Pool Algaecide
1839-90 5% BTC 2125 Swimming Pool Algaecide
1839-92 10% BTC 2125 Swimming Pool Algaecide
1839-210 BQ451-1P Algicide
EPA Reg. No. 1839-141 is a high concentrate version. This could be beneficial for larger pools and industrial commercial pools. EPA Reg. No. 1839-141 and 1839-210 have a blue dye allowance in the formula.
If interested in sublicensing one of these algaecide end-use products, Stepan is here to help.
