Joe wrote:

Have your water analyzed (a freebie in some areas) and consider
getting a water softener. Hard water is more damaging to faucets and
fixtures than you realize, especially the much more complicated types
now in the stores. Softeners are some work, but ask neighbors who have
them about the benefits and that may help you decide.

A softener would be good, but you should know that the detergent manufacturers
under pressure from certain state environmental agencies have removed phosphates
from dishwasher detergents nationwide.

If you pick up a box of true TriSodium Phosphate (TSP) powder (red box) - not
substitute TSP and mix about one part TSP with 3 parts detergent, you may find
you lose the film. You can also use Sodium Tripolyphosphate. Both are called
binders. They keep any minierals in the water from attaching to the dishes.