water softness
Is it a public "city" water supply or is your that your individual home which draws from the springs?
With your water being sourced from an "underground spring" you are likely to have moderate amounts of dissolved calcium. As water flows through the aquifer (rock formation underground that yields water) it literally dissolved the rock. It depends how long your water has been in the aquifer. We call it "residence time." Depth, thickness of aquifer, location of area of recharge, etc. can all affect hardness. So just saying you have underground springs does allow us to specifically state your water hardness.
Public water supplies using surface waters, such as rivers and lakes, are generally are substantially softer.
It's quite possible you could benefit from a softener. If you can't get the information on your harness value from your utility, many of the home improvement stores, who sell softener, have home test kits.
Dishwashers tend to be affected more by water hardness than other appliances. Rinse agents can help prevent spots if the water is only moderately hard. They mainly help prevent spotting from mineral deposits, but they don't help actually in cleaning dishes in the washing process. Unfortunately, detergents and hard water don't get along. Hard water can greatly reduce what your detergent is able to do.
Below you can see a chart of hardness. In Oak Ridge, we had hardness of 10, and the dishwasher worked fine. The rinse agent prevent any spots. But when I finally put a softener in there was a noticeable difference in sparkle, especially of the glasses. But the dishwashers I had did just fine even before putting the softener it. But I am one of those that really like glisten and sparkle so I went ahead with the softener. It helped with the laundry and keeping the bathroom fixtures clean, anyway.
In my area of Ohio, where I used to live, we had hardness in the range of 24+ grains per gallon. You really needed a softener there. White calcite deposits were not only left on the dishes, but eventually even built up inside the machine over time.
