State the disadvantages of using hard water.

1. Furring of tea kettles is caused by sediment formed from boiling hard water. This fur is carbonates of calcium and magnesium.
2. Hard water is unfit for washing purposes because it is difficult to form lather with soap. Scum may form in a reaction with soap, wasting the soap.
3. Hard water is not suitable for producing steam. Solids in hard water incapable of changing into steam get deposited on the inner walls of the tubes. Hence, the tubes become narrower and eventually less steam is produced.