What is Hard Water?
Hard water refers to water that contains high levels of calcium, magnesium and other dissolved minerals.
These minerals can leave unsightly limescale deposits on surfaces, clog showerheads and faucets and make clothes yellow and dingy.
Here is an example of what these stains could look like:
This data represents mean hardness of water based on major-ion chemistry concentrations as measured at various locations. Actual hardness on the scale of individual homeowner property may be different based on a number of factors, including location of water source and presence of treatment facilities, and may not be the same as what is shown here. For more info, see USGS