Our water is considered soft. We generally maintain a 1-2 grains of hardness in our finished water. This means that less soap is needed to do things like washing our hair, cleaning our clothes, and running our dishwashers.
Consult your dishwasher manuals to be sure just how much detergent is necessary to wash your dishes. You will be pleased to find you will probably need to use half of the detergent that will fit in the reservoir since dishwashers are made universally for all types of water. You may be wasting money and etching glasses by using too much detergent.