is hard water rust
Learn how to remove lime buildup from your dishwasher. One area in the kitchen that can quickly lose its sparkle often goes unnoticed because of its hidden location: the inside of the dishwasher. Lime buildup is fairly common in regions where high mineral content causes hard water. As water travels underground, it can become exposed to various minerals found in soil and rock, including calcium, magnesium, iron, copper and rust â each of which can play a significant role in the quality of the water.