COSORI Electric Kettle with Upgraded Stainless Steel Filter and Inner Lid, Wide Opening Glass Tea Kettle & Hot Water Boiler, LED Indicator Auto Shut-Off & Boil-Dry Protection, BPA Free,1.7L, Black

What is Hard Water?- Hard water is a kind of water that contains calcium or magnesium mineral ions that often in the form of carbonate. – These ions do not pose any health threat, but they can engage in reactions that leave insoluble mineral deposits. How to Descale/Clean the Kettle? 1. Filling the kettle with 1 cup of vinegar or lemon juice and 2 cups of water. 2. Boiling the liquid and leave it for 2 hours, then use a cloth to clean and wipe. 3. Rinse the kettle with clean water, and dry with a soft, clean cloth. 4. Repeat as needed.Note:It’s normal if your kettle exposes spots or rust on the stainless steel bottom after the first use if the water quality in your area is so hard. ​