The dishwasher was not getting dishes clean

We had tried to use dish washer cleaners, and they would work for a time, but we started spending more money on cleaner than we wanted. I ordered and then I replaced the lower spray arm. It took a little effort to get the top screw off, due to hard water deposits. The new one went on very easily, just screwed right in like the old one. It's working great and I really don't mind not getting a new one or paying for a service call!!!