For yellow or brown buildup (caused by high iron or manganese content in water) do periodic cleanouts with a product designed to remove lime deposits or with citric acid crystal. Citric acid crystals are available from a druggist or in a hardware store. Remove all items from the dishwasher, put one cup of the crystals in the bottom of the dishwasher and run it through a normal cycle without dishes. Follow with a full cycle detergent wash and an empty dishwasher. Using the recommended amount of granular Cascade will retard staining.