What minerals are primarily responsible for causing water hardness?

The primary minerals responsible for causing water hardness are calcium and magnesium. Water hardness is a measure of the concentration of divalent metal ions, particularly calcium (Ca²⁺) and magnesium (Mg²⁺), that are present in water. When water percolates through soil and rock, it can dissolve these minerals, leading to an increase in hardness.

Hard water containing significant levels of calcium and magnesium can cause various issues, such as reduced effectiveness of soaps and detergents, as well as scaling in pipes and appliances. This can lead to higher maintenance costs and reduced efficiency in water-using appliances. Therefore, understanding the role of these specific minerals in water hardness is essential for managing water quality and its associated impacts effectively.