Swimtrine Plus is a highly concentrated copper based algaecide especially designed to kill mustard and green algae. When used regularly, it also prevents the regrowth of all types of algae. Swimtrine Plus contains 9.3% active copper content - making it America's most concentrated fast-acting algaecide. Features: Triple chelated copper formula stays active and provides algae control between treatments Effective over a wide pH range Will not foam Does not clog filters Compatible With: Bromine, chlorine, and ozone.