Pond Boss Forums GENERAL QUESTIONS Water chemistry copper concentration

If you are not testing with atomic absorption method then you want no measurable copper in the water. Even low doses of chronic copper will produce internal stress to fish but not kill them right away. different species of fish have different killing doses from CuSO4. If the copper is killing fish what do you think it did to all the other micro-organisms lower on the food chain in the pond??. Free Copper ions should fairly quickly form copper carbonate and percipitate to the bottom. However this will depend on the hardness of the water.