Because usually the water used in the health pot is hard water. Scale is a common name for mineral salt precipitation, and its main components are water-insoluble compounds such as calcium carbonate, calcium sulfate, magnesium hydroxide and magnesium carbonate. The reason why health pots are prone to scale is because the water used in health pots is usually hard water. Scale is reflected in the water quality index by hardness, and the national standard stipulates that the hardness of drinking groundwater should not exceed1000 mg/L.