The lethal toxicity of copper to rainbow trout in hard water was found to be related to the total concentration at which soluble copper. Cu2- and CuCO3, was present in the water, rather than to the concentration of either of these two forms alone. It is suggested that, except in the presence of highly toxic organo-copper compounds, from a knowledge of the cupric ion concn, the pH, and the alkalinity of a water, the total concentration of soluble copper can be calculated and hence the toxicity of that water determined. © 1974.
Shaw, T. L., & Brown, V. M. (1974). The toxicity of some forms of copper to rainbow trout. Water Research, 8(6), 377–382. https://doi.org/10.1016/0043-1354(74)90051-7