What is a common sign that water might be hard?

A common sign that water is hard is the presence of scaling on fixtures. Hard water contains high levels of dissolved minerals, primarily calcium and magnesium. As water evaporates or is heated—such as in water heaters or on showerheads—these minerals precipitate out and form scale, which is typically seen as white or chalky deposits. Over time, this scaling can accumulate and lead to reduced efficiency in appliances and plumbing systems.

In contrast, persistent foam formation with soap is often a sign of soft water rather than hard water, as hard water tends to react with soap and reduces its foaming ability. Strong chemical odors do not directly indicate hard water; they could suggest contamination or other chemical imbalances. Low pH levels typically signify acidic water, which does not correlate with hard water conditions.