Water hardness is a measure of the concentration of certain minerals in water, primarily calcium and magnesium, but also including other metal ions. Hard water contains a higher concentration of these minerals, which can have various effects on household appliances, plumbing, and even the effectiveness of soap and detergent. In contrast, soft water has a lower concentration of these minerals. The hardness of water is commonly expressed in grains per gallon (gpg) or milligrams per liter (mg/L), also referred to as parts per million (ppm). While not harmful to human health, hard water can lead to scale buildup in pipes and water heaters, reducing efficiency and lifespan. Water softening methods are often employed to reduce hardness, improving the performance of soap and extending the life of appliances and plumbing systems.Â