Hard Water deposits
Hi Shannon, CC Powder is not a good detergent with water that hard, yes a rinse aid dispenser will mask the water spot problem, but you really need a better detergent, or a home water softener, or you can add phosphates to the CCP, it can also help if you put the dishes in really covered with oils and lots of sugars etc, but it is hard to get enough of these soils in a load on a regular basis.
I would try a TOL tablet in the main wash dispenser and also fill the open cup with the CCP and see how that does.
John L.