Your first line of defense is a kitchen staple your grandmother swore by: white vinegar. Fill a dishwasher-safe cup (like a glass measuring cup) with two cups of vinegar and place it upright on the top rack. Run a hot-water cycle—no detergent, no pre-rinse.
The acetic acid in vinegar gently dissolves the mineral bonds like a hot knife through butter. After the cycle, open the door and breathe in that tangy, clean scent. It’s the smell of victory over hard water. Pro tip: Do this monthly if your water is “hard” (over 7 grains per gallon).
