at your local restaurant supply(phone book) they got stuff to use in the restaurnat dishwashers, sold in quarts and gallons
minerals disappear is 5 seconds
or else go to your local hardware store or plumbing supply and get lime away or similar product. it wont work as fast as the restaurant stuff, but will indeed work
follow directions on bottle
as always, i dont recomend shopping at home centers. shop your local stores. they listen to your problem and get your problem solved