Blue Crystal disinfecting tablets are a special microbicide developed exclusively for use in residential wastewater treatment applications. Designed for positive disinfection during low, sustained, variable and intermittent flow rates that are common to residential systems, the potent Blue Crystal formulation reduces 99% of bacteria within the first ten minutes of contact. Blue Crystal tablets are a preferred, safe alternative to dangerous liquid and gas disinfection systems. When used as directed in any approved gravity flow chlorinator, Blue Crystal tablets allow residential treatment systems to meet regulatory disinfection requirements with a product that is inexpensive, safe and easy to use. Blue Crystal disinfecting tablets are packaged in easy to open, resealable 5 lb., 10 lb. and 100 lb. Department of Transportation approved containers.