What is hard water?
Hard water is labelled ‘hard’ not because there’s any difference in rigidity, but because of its mineral content. During the water cycle - the journey water takes to get to our homes - rain water percolates through rock such as chalk and limestone, and picks up minerals on the way. If those picked up minerals are calcium and magnesium, we speak of hard water.
Though hard water isn’t unhealthy to drink, it causes lime scale deposits, which is why we speak of "suffering" from hard water.