Hard water is water that contains high levels of minerals, primarily calcium and magnesium. These minerals dissolve into the water as it passes through soil and rock. While hard water is not harmful to health, it can cause issues in households, such as scale buildup in pipes and appliances, which can reduce their efficiency. When using hard water for cleaning, it may not lather well with soaps and detergents, making it less effective for washing. Many people choose to install water softeners to reduce hardness, which can help improve the performance of appliances and cleaning products.