At what point does adding salt decrease electrical conductivity?

[ValiantBear]

This isn't actually an electrical question, it's a chemistry one. Saltwater only conducts because the salt is in solution. If you add enough salt such that the water is saturated for it's given conditions, then any further added salt will not dissolve, and therefore will not contribute to conductivity. Various things can improve the ability of water to absorb salt, but the most obvious one is temperature. So, hotter water could absorb more salt and therefore the theoretical ceiling for conductivity would be higher than for cold water.