• It can cause "scale" to form on the inside of pipes, water heaters, tea kettles an­d so on. The calcium and magnesium precipitate out of the water and stick to things. The scale doesn't conduct heat well and it also reduces the flow through pipes. Eventually, pipes can become completely clogged.
  • It reacts with soap to form a sticky scum, and also reduces the soap's ability to lather. Since most of us like to wash with soap, hard water makes a bath or shower less productive.