This paper discusses fundamentals of copper pitting using a series of simple electrochemical devices and exposures, resulting in improved understanding of copper pit initiation, propagation, and death. It was determined that the formation of cuprous oxide, cuprous chloride, or sulfides next to copper metal can all initiate pitting currents in Type I waters, and that cuprous chloride is the most destructive in this type of water. However, in Type III waters, passivating currents were observed in the presence of cuprous chloride, and sulfides were especially destructive in this type of water. Additionally, it was determined that pH adjustment is probably the most effective control method in Type I waters when cuprous chloride initiates pitting, but that pH increases are not beneficial in Type III water, supporting results in two other studies with similar water type. In this study, however, the favorable effect of chlorine was separate from its disinfectant properties.