Home Remedies for Washing Dishes in Hard Water

If you've got hard water, you may have noticed a milky white residue on your dishes after you wash them. Short of installing a water-softening system, you can use one of dozens of commercial products to solve the problem of dirty-looking dishes. You could also go the homemade route for a solution that's just as easy, less expensive, and, ultimately, better for the environment, that still leaves your dishes looking clean and sparkling.

Acid Versus Alkaline

The white film and spots on your dishes are mineral deposits from the hard water, and they're almost impossible to remove by scrubbing alone. All commercial rinse aids and additives work by using an acid to help cut the mineral deposits during the rinse cycle. Typical dish detergents have a relatively neutral pH of 7 or 8. Homemade dishwashing recipes tend to be higher, in the 8 to 10 range, thanks to the use of sodium borate or sodium carbonate, both very alkaline.

When to Use a Rinse Agent

In mild hard water, using an acid during the wash cycle can be enough to prevent mineral deposits. In extremely hard water, you may need to use an acidic rinse agent in the final rinse cycle to prevent any mineral deposits on dishes, which, in a dishwasher, means a liquid rinse agent. When washing dishes by hand, you can simply dissolve the rinse agent in a sink of clean water.

Using Vinegar

Vinegar is a natural solution to hard water deposits on dishes. To wash dishes by hand, use 1 cup of vinegar in the rinse water. If your water is very hard, you can also use 1/2-cup vinegar in the wash water. In the dishwasher, simply pour vinegar into the rinse-aid dispenser if it has one; otherwise, pour 1 cup of vinegar into the bottom of your dishwasher as the final rinse begins. If your water is very hard, you can also add 1/2 cup of vinegar at the start of the wash cycle.

Using Citric Acid

Food-grade citric acid is another natural choice for conquering hard-water deposits on dishes. You can find food-grade citric acid in your local grocery store, health food store or a specialty beer retailer or brewery. If you're using granules, add a tablespoon of granules to your rinse water when hand-washing dishes. If using a dishwasher, add 1 to 2 tablespoons of citric acid granules to the usual soap dispenser and pour your regular dishwasher detergent into the secondary soap cup and wash as usual. If you have exceptionally hard water, make sure you are also using a rinse agent during the rinse cycle. You can dissolve a tablespoon of citric acid granules in a cup of water and add the mixture to your liquid rinse-aid dispenser.

Baking Soda, Sodium Borate, Salt and Detergent Ingredients

Since most homemade and commercial dishwashing solutions are alkaline, adding an acid during the wash cycle can reduce the effectiveness of the washing agent. For normal daily dishes, this shouldn't be a problem, and you will still have clean dishes. In hand-washing, you might see fewer suds when adding an acid to the washing. Some homemade detergents use salt to help soften water, but salt should not be used during the rinse cycle as it can leave deposits of its own.