"Hard" water is typically defined as water that has a high mineral content. While large amounts of calcium are often to blame for the development of hard water, high stores of copper and magnesium can also contribute to poor water quality. It should be noted that laboratory experiments have concluded that there was little appreciable difference in the tensile strength and elasticity of hairs after they were treated with hard and soft water. Anecdotally however, water with a high mineral content might make your hair feel drier and more brittle, which can contribute to hair loss. If this is your experience there are some steps you can take.
