Crystal Plex is a chelated Copper solution designed to attack and destroy algae, and some aquatic plants including Hydrilla, Duckweed, Pondweed, etc. The unique properities of Stabiltrol allow Crystal Plex to remain active in the water column for over 30 days until used through interaction with aquatic growth. Apply one gallon per surface acre of water. When water temp is above 60 degrees treat half the pond, wait 10 days before treating the other half. Copper sulfate is the active ingredient which depletes oxygen levels in water.