Open the Frigidaire dishwasher and remove the bottom rack.
Grab the flat edges of the main filter and lift it out of the dishwasher. The main filter is located on the dishwasher floor.
Separate the cylinder-shaped cup and fine filters from the main filter and rinse the filters under running water. Gently scrub away any debris from the filters with an old toothbrush.
Reassemble the dishwasher filter assembly. Place the fine filter in the dishwasher, followed by the cup filter and the main filter. Replace the bottom dish rack.