Calcium in particular causes the ugly scaling you see on your faucets and tubs. O nce armed with the knowledge that you HAVE hard water and that you have to DO something about it, you must now be held hostage in your home by the water softener sales people, who will parade through your house, and try to sell you a softener which seems large enough to take care of a small pharmaceutical plant's water needs. They will also perform some mumbo jumbo at your kitchen sink with solutions of many different colors to try and demonstrate just what their unit will do for you, quoting things like grains per gallon per day, and reverse osmosis. Spend a few minutes thinking about your family's water usage. So multiply 75 by the number of people in your house.
Water hardness is measured in the units called grains.
The water guys won't tell you this, but you can measure the hardness the same way they do by going to a pool supply store and purchasing a water test kit. You can test the chlorine level and the hardness very easily for about 6 dollars. Or better yet borrow the stuff from someone who has a pool, you'll only need to use it once or twice. A more expensive solution would be to put a pool in, that way you'd have to have them on hand at all times. All the test involves is taking a small amount of your water and adding a few drops of a chemical to it, which turns it pink, then adding another chemical to it drop wise until the color changes from pink to blue.