Understanding Copper Sulfate’s Effect on Ponds

Copper sulfate is an inorganic compound that is used as a biocide to kill bacteria, algae, roots, plants, snails, and fungi. Copper sulfate is highly toxic to fish. Even at recommended rates of application, this material may be poisonous to trout and other fish, especially in soft or acid waters. The toxicity of copper sulfate depends on the copper content. As an element, copper can persist indefinitely. Copper sulfate has been registered for use in pesticide products in the United States since 1956.