Seawater is an alternative to freshwater, which is scarce for copper mining in northern Chile, but it has components that may be problematic for hydrometallurgical processes. This work determines the influence of seawater on the solid liquid equilibrium for acid solutions of CuSO4 at different temperatures, (298.15 to 323.15) K, and its effect on physical properties (density, refractive index, ionic conductivity, and viscosity). The measured properties show an average difference between CuSO4 in seawater and CuSO4 in freshwater of 1.42 % for solubility, 1 % for density, 0.29 % for refractive index, 24.61 % for ionic conductivity, and 5.61 % for viscosity. In addition, the physical properties of unsaturated solutions composed of CuSO4 in acidic seawater at different temperatures, (298.15 to 323.15) K, and molalities, (0.1 to 1.8) m, were measured. The experimental data for the physical properties were correlated using Othmer's rule. This equation yields a good fit and predicts saturation data with the exception of ionic conductivity, where the Casteel-Amis equation is recommended. The solubilities and properties for both systems (acidic seawater and freshwater) are similar. This observation suggests that seawater may be appropriate for leaching with no major short-term effects.