Dear student. The advantages of hard water are - 1.Hard water is good for making our bones and teeth stronger when we drink it. This is because it contains high amounts of calcium and iron, which are good for the bones and teeth. 2 Hard water does not dissolve lead, and as a result of this it does not lead to lead poisoning. 3.Hard water is fit for drinking as it tastes better than soft water. 4. Detergents work well in hard water, than in soft water. So to remove harsh stains,using detergents, hard water is most suitable. Regards