Hard Water's Hidden Cost: Beyond Hair Care Hard water contains higher concentrations of dissolved minerals like calcium and magnesium, according to Desmond Tobin, professor of dermatological science at University College Dublin.
These minerals can cause problems for our hair – and beyond. As Tobin notes, hard water is often characterized by its ability to make soap lather up with difficulty, forming a kind of scum rather than bubbles.
The impact on hair care has been well documented: mineral deposits left behind after washing can leave hair looking duller and feeling rougher. But the effects don't stop there.