What's the most practical thing to do to eliminate hard mineral sticking my kettle formed by a spring water?

Our water source is deepwell and we have spring water. Spring water aculates white minerals or substance that sticks on the kettle as we boil it. What's the best thing to do except scratching it with steel brush. The spout is almost covered by white substance and covers the holes which flows small water when I pour it. It's hard to clean because I have to punch it with small pointed object to eliminate or lessen it. Have you any idea?