When we moved here, we were lucky to have a friend and our landlady explain the ins and outs of how to use German dishwashers properly. I know your thinking “uh, you are retarded!”, but seriously, they require care different from back in the U.S.
Yes, really! There is a screw off lid in your dishwater at the bottom where you need to fill it with salt. There is also usually a little symbol on the timer inside that says it needs salt. Now, don’t be thinking “table salt” because that will get you nowhere. You must buy the “Salz” in the local grocery store, the Natex, or you can even pick it up at Schinnen. In each store it is located next to the dish soap. Most of the time it comes in a red box. You might need two boxes to fill up the reservoir.
Here’s a YouTube post by another military wife showing the process of putting the salt into the dishwasher. The salt softens the water, allowing the detergent to work more efficiently and helping to prevent lime scale.