The most common treatment of blue-green algae in an open dugout or pond is with a registered product containing copper sulphate. The copper sulphate kills the blue-green algae, releasing toxins into the water. Therefore, it is recommended that 12 to 14 days should pass prior to any livestock, pet and/or human contact with the contaminated water. Lime, alum and ferric chloride are coagulation products that bind to all bacteria. Once bound, the bacteria clumps together and sinks to the bottom of the dugout. While these products work to remove blue-green bacteria from the water surface, the dead blue-green bacteria cells can rupture, releasing toxins into the water.
