First of all, hard water is not dangerous for human beings. In fact, all living things depend on the minerals in water to sustain life. The minerals in water and the amount of each mineral in water determines the softness or hardness of water. Technically, the measure of minerals is computed using PPM or parts per million. With respect to hardness, you measure the PPM of calcium. The higher the number, the harder the water. Generaly speaking, if you have water that is 150 ppm or less, you have soft water. If you have more that 450 ppm of calcium in your water, it is very hard. Most water in the United States is somewhere in the middle. This has a great deal to do with how much limestone, manganese, and magnesium are in the water shed below you.
Berkey water filters are designed to allow beneficial minerals to pass through into your clean water chamber. This is a good thing because your body can use those minerals. However, many people make use of soft water systems to remove minerals in the water that create lime deposits on pipes, faucets, and other plumbing. They also use soft water to make soap and other cleansers more effective. This process uses salt, which can have a negative effect on the Black Berkey water filter elements. Soft water tends to clog the filter elements. Therefore, we recommend that you use a bypass valve and use water directly from the source rather than run soft water through your Berkey water filter.