The Best Way to Solve Hard Water Laundry Problems

water with suds

The Spruce / Ulyana Verbytska

Hard water can leave stains on clothes, sheets, and towels and make them look dingy and feel rough to the skin. You might also notice a powdery residue left on just washed clothing, which is also due to hard water. Learn how to handle hard water stains on clothes and get better and cleaner results for your laundry.

What Is Hard Water?

Hard water is found in 85 percent of America. Hard water is usually defined as having high levels of calcium and magnesium; the greater the concentration of these minerals, the harder the water.

With a high concentration of these minerals in the water, unless the water is treated, the calcium and magnesium attach to the fabric in a laundry load and leave clothing and linens feeling stiff and covered with a residue that dulls color. In excessively hard water, the fabric fibers can actually break and create holes due to the amount of mineral coating.

If you are on a municipal water system, the officials can tell you the level of mineral content in your water supply. There are also companies that will test your water supply. Testing is particularly important if you use well water.

Hard Water Laundry Problems

  • Dinginess, graying, or yellowing of fabrics.
  • Soil build-up on clothes that doesn't wash away.
  • Stiff, harsh to the touch fabrics.
  • A weakening of fibers causing tears.
  • White or gray streaks on colored fabrics.
hard water laundry

The Spruce / Alison Czinkota

How to Select and Use Laundry Detergents in Hard Water

In hard water, most of the ingredients in any powdered laundry detergent become attached to the minerals in the water rather than cleaning the clothes. This means that up to 30 percent more detergent must be used and at a higher water temperature than usual to get satisfactory cleaning results. Having to use more detergent is expensive and higher water temperatures can damage clothes and costs more money in energy bills.

You will have better cleaning results with a liquid laundry detergent because all brands contain nonionic surfactants that are resistant to water hardness. Because there is no ionic charge, the product will not precipitate out and cause a scum on fabrics. Whether you choose liquid or powder, you'll see better results if you select a heavy-duty detergent over a bargain brand that offers the most cleaning ingredients.

You can also add 1/2 cup laundry borax to each load. Borax provides water softening by producing a soluble calcium complex (forming a chelate with the minerals so that they are no longer available for reactions) and boosts surfactant performance by preventing precipitation of a calcium/surfactant complex.

Homemade laundry detergents often rely on a pure soap as a basic ingredient. Unfortunately, soap does not perform well in hard water. If making homemade laundry detergent for use in hard water areas, increase the amount of borax by at least one third to produce better cleaning. You may need to test and adjust your formula to include even more borax.

borax next to laundry detergent

The Spruce / Ulyana Verbytska

How to Make Laundry Water Softer

So rather than using more detergent, water can be softened in the washer with nonprecipitating ion-exchange water conditioners, commonly sold in grocery stores simply as water softeners or water conditioners. If you cannot find them locally, water softeners can be purchased online.

Water softener systems that exchange sodium for calcium and magnesium may also be connected to the water supply lines. However, anyone on a sodium-restricted diet should consult a physician before adding a water softener system to lines that supply water for drinking and cooking because the sodium content of the water will increase.

Two studies, published in 2009 and 2010, conducted by the independent testing firm Scientific Services S/D of New York and funded by the Water Quality Research Foundation (WQRF), reveal that by using softened water in washing machines, detergent use can be reduced by 50 percent. In softened water, water temperatures can be reduced to 60 degrees F cold water, instead of 100 degrees F hot water, and still achieve the same or better stain removal and cleaning.

Researchers used varying levels of hardness and several different name brand detergents in washing machines. It was found that significant savings were noted for all levels of hardness, even hardness as low as five grains per gallon. In a look at stain removal, half to the entire amount of manufacturers' recommended levels of detergent was added. Water hardness ranged from none to 30 gpg, and wash temperature was 60, 80, and 100 degrees F. It was found that using softer water is better at removing stains than increased water temperature or more detergent being used.

Fixing Hard Water Laundry Stains on Clothes

If you have not installed a mechanical water softening system, to remedy problems that have already occurred, fill the washer with the hottest water appropriate for the fabric. Add four times the normal amount of detergent and one cup water conditioner. Agitate just long enough to wet the clothes. Soak overnight or for about 12 hours. Drain and spin without agitating. Launder the garments, using a regular cycle, no detergent, and one cup of water conditioner.

If needed, repeat using one cup of water conditioner and no detergent until no suds appear during the rinses. In order to remove all dinginess, it may be necessary to launder with one cup water conditioner and a bleach which is safe for the fabric, following package instructions.

To remove white residue mineral and detergent stains, soak fabrics in a solution of one cup white distilled vinegar to one gallon of water for 30 minutes. Rinse thoroughly, then launder.

Chlorine Bleach and Hard Water

Many times hard water contains iron particulates which when combined with chlorine bleach produce iron oxide or rust which can stain clothes. Learn more about how to handle rusty water and how to remove the stains using a rust stain remover.

Article Sources
The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Hardness of Water. U.S. Geographical Survey.

  2. Guidelines for a Low Sodium Diet. University of California.

  3. Softened Water Benefits Study. Water Quality Research Foundation.