ACO is an Active Catalytic Oxidizer that works by using the energy of the sun or UV light to catalyze the formation of free radicals to disinfect pool water. The radicals work just like chlorine to remove pollutants but they do not form combined chlorine.
ACO is not consumed in the process; it just makes what naturally happens much more efficient. ACO also protects chlorine from photolysis by sunlight and makes it last three times longer in outdoor pools. ACO does the same as cyanuric acid, but instead of reducing oxidation capacity, ACO amplifies the disinfection of water.