Argos is a liquid copper-based formulation containing ethanolamine chelating agents to prevent the precipitation of copper with carbonates and bicarbonates in the water. Argos effectively controls a broad range of algae. Argos has also been proven effective in controlling the rooted aquatic plant, Hydrilla verticillata. Waters treated with Argos may be used for swimming, fishing, further potable water treatment, livestock watering or irrigating turf, ornamental plants or crops after treatment.