How Do We Control Microbes? Reduce microbes entering the systemPretreatment with chlorine or other antimicrobialControl nutrients entering the systemProcess leaksPhosphate and nitrogenControl sunlight entering the waterApply antimicrobial chemicals to the cooling systemOxidizingChlorine, bromine, chlorine dioxideMostly non-specific across organism typesNon-oxidizingMany types – Isothiazolin, DBNPA, Glutaraldehyde, Quat Amine & PhosphoniumEffectiveness is more specific to the organismCan be difficult to permit