We live in the far western Chicago suburbs. When we moved here we got our water from a community well (operated by our town.) The water was very hard and in add

We live in the far western Chicago suburbs. When we moved here we got our water from a community well (operated by our town.) The water was very hard and in addition had a lot of sulfur and iron. (A water heater would change the sulfur compounds so they smelled like rotten eggs.) IIRC the hardness was about 450 ppm. I installed an ion exchange water softener that fed the hot water heater and cold water to the laundry. We continued to drink hard water and use it for cooking. Some years later we were switched to a supply that was piped from Lake Michigan. That was about 135 ppm hardness and did not have the sulfur and iron content. Didn't need the water softener any more but we still use a water filter pitcher to remove chlorine and bad flavors from the water. (The filtering activity of zebra mussels clarified Lake Michigan and allowed algae to grow at the depths where the water intakes were located. The algae left a musty taste in the water at times of the year when it flourished.) Even in the same location, water chemistry can vary a lot.