If you have lived within Jacksonville, Florida or surrounding areas, you may have noticed a white powdery substance forming within the appliances, usually the dish washer or shower area. What you are seeing is high mineral content. Hard water is formed when water percolates through deposits of limestone and chalk which are largely made up of calcium and magnesium carbonates. These minerals dissolve into solution and are carried through the water into plumbing distribution systems, thus the term hard water. Very hard water has a measurable level of 7 to 10.5 grains per gallon of hardness minerals.