Laundry basics: detergents & water temperature

It turns out the key to clean clothes isn't always printed on the label. Here's some info on how to make the most of your next laundry load.

A washer uses these three kinds of energy to remove soil from clothing:

• Mechanical energy comes from the washing action of the machine, either from an agitator or gentle tumbling motions.
• Detergents, bleach and other additives provide chemical energy.
• Thermal energy is supplied by warm or hot water.
• If you reduce any one of these elements, another must be increased. For example, if you lower the water temperature, you need to increase the wash time to compensate.

• More suds do not equal better cleaning, nor is more detergent necessarily the solution to a tough cleaning problem.
• Use low sudsing detergent if you have soft water to help rinse detergent during the latter cycles.
• While manufacturers almost always include a scoop that's sized for one load, that load is based on an average. Rather than rely on the scoop, consider each load's size, how dirty the clothes are and how much water will be used.
• The hardness of the water affects the amount of detergent you should use.
• As a rule of thumb, if the load is very dirty or very big, or if hard water is a problem in your area, add more detergent.
• Put the detergent in before the clothes. It'll dissolve more quickly and clothes will come out cleaner.

• Knowing how hard your water is makes it easier to make the correct adjustments.
• One way to determine water hardness is to buy a test kit at a hardware store.
• You can call your local water utility for a reading, which is usually measured in grains per gallon (gpg). A reading of zero to three gpg is considered soft, four to nine gpg is average and 10 gpg and above is hard.

Washing laundry in cold water saves energy, but clothes usually don't get as clean as with warm water. Detergents usually won't work well in water colder than 18°C, but here's some ways to compensate:

• Liquid detergents dissolve more quickly in cold water than granulars, so they clean more effectively in cold-water laundering.
• You can improve your cold-water results by using bleach judiciously, pre-soaking dirty clothing and pre-treating any stains.
• When it's cold outside, you can offset the water's below-normal temperature by running on the warm cycle. The mixture of very cold water on the warm water setting may average out to what would be considered a cold setting.

Detergents and water temperatures play a key role in laundry. By knowing how to control each, your loads can be cleaner and less expensive.