First of all, I pulled off (Unscrewed) the three (Lower, middle and upper rotating spray arms) and soaked them in warm water to get rid of any hard water or cleaning solution build-up, and then I cleaned out any of the small jets which were still clogged. The lower and upper spray arms came out fine but the middle sprayer even though seemingly clean would not rotate when water flushed through it. Dishes and cups/glasses were cleaning better but there was still a residue left because the middle spray really wasn't operating correctly (By not rotating).........Ordered a new middle spray arm from Appliance Parts Pros, it arrived within days, I installed it and my dishwasher cleans like a new unit....Very satisfied with the results and for only around nine dollars!