The hardness of water refers to the content of calcium and magnesium ions in water. The harder the water, the more salt the water softener needs to consume during the softening process. Therefore, in areas with harder water, the use of salt blocks will be shorter and may need to be replenished monthly or even weekly.

The best water softener brands: 1. Culligan (an old water treatment company with a history of more than 80 years), 2. Kinetico (famous for its non-electrically driven double-cylinder water softener), 3. Fleck, 4. Whirlpool, 5. GE Appliances, 6. CHUNKE.