Testing the water hardness of drinking water is to ensure the safety of drinking water. Too much water hardness will affect chewing and digestion, while too little water hardness can make the drinking water soft and affect one's drinking habits

Testing the water hardness of the tap water plant is to ensure the quality of the tap water, to ensure the mineral content of the tap water, and to prevent the water hardness from being too high or too low, so as to ensure the quality and safety of the tap water

If the water hardness is too high, it may damage the pool hardware and affect the service life of the pool; if the water hardness is too low, it will make the pool water very soft and the alkalinity in the pool water will become high, which is harmful to the human body

Water hardness and pH value of aquarium water is an important indicator of home aquarium, water hardness is too low will affect the growth and development of fish, water hardness is too high will also make the water environment becomes unsuitable