Powder chlorine Trichloroisocyanuric acid It is a disinfectant used by adding directly to the pool water. It can be used in shock chlorination applications with its high amount of active chlorine. It is easy and economical to use. It is a pool chemical used for routine chlorination in pools. It should be used together with a shock chlorinating agent at the beginning of the season, in weekly shock chlorinations, in winter preparation and as an algae preventative. It is used for continuous disinfection of pool water thanks to its slow dissolution in water. It does not leave any waste in the water.