The good news is that hard water is a relatively easy condition to treat. The treatment process is easy to administer as a homeowner and the results are often very good. Please look into installing a water softener if you wish to reduce or eliminate the source of hardness. Although the hardness levels can vary depending on the source of the water being on any given day, for design purposes, the hardness levels are approximately 250 mg/l or 15 grains per gallon.
There are numerous cleaning products on the market which advertise to clean surfaces that have an accumulation of a calcium precipitate.