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The modern economy doesn't leave a lot of room for unnecessary waste. A penny wasted here or a nickel there can add up to hundreds of dollars over the course of a year. An often overlooked budget waster is hard water and its effect on laundry. Hard water is often not an "obvious" problem to people who have not had the opportunity to compare it to soft water. It is usually difficult to see or taste any difference between hard and soft water. The minerals that make water hard (calcium and magnesium) are usually tasteless and completely dissolved. The differences between hard and soft water become more obvious in bathing and cleaning, where hard water leaves a residue when combined with soap called "soap curd," which must itself be cleaned off. Hard water has similar effects on laundry.
Hardness minerals affect laundry in a gradual manner often not obvious in today's automated washing processes. People accustomed to hard water may not notice the increased detergent use, faster fading of colors or yellowing of whites, shortened fabric life, greater demand for hot water, increased wear on the washing machine, and extra wash and rinse cycles. But the waste is still there, slowly working away at the family budget. Fortunately, hard water can be softened, and soft water virtually eliminates these problems.
What is Hard Water?
The U.S. Department of the Interior has established levels for the classification of hardness based on the grains per gallon (gpg) concentration of these minerals. To put grains per gallon in perspective, a typical aspirin contains about 5 grains of material. Were this to be dissolved in a gallon of water, it would add 5 gpg of material to the water. Water in the 1 to 3.5 gpg range is considered slightly hard. If the water is in the 3.5 to 7.0 gpg range, it is considered to be moderately hard; hard water being between 7.0 to 10.5 gpg. Very hard water is defined as water with concentrations of dissolved minerals in excess of 10.5 gpg. The harder the water, the more it impacts laundry; and even moderately hard water can make a difference.
Wasteful Hard Water
Unfortunately, hardness minerals combine with soap to form an insoluble "curd," which can remain as a residue on washed laundry. This is similar to the difficult-to-clean residue found on bathroom tubs, sinks, and tile in hard water areas.
Hardness also tends to counteract soap's alkalinity, which reduces its cleaning ability and requires the use of greater quantities to get laundry clean. A partial solution to this problem is the addition of "builders" such as complex phosphates, silicates, or sal-soda, which can be added to counteract hardness. Builders boost the alkalinity of the wash, improving its cleaning ability, and helping to neutralize acid soil and hardness minerals. However, builders do not prevent the formation of soap curd.
Alone, synthetic detergent is generally neutral and does not create the alkaline cleaning environment soap does. Most modern detergents also contain builders, but in much greater quantities than soap. Unfortunately, the builders tend to be consumed in softening hard water. This limits their ability to clean, and requires greater quantities of detergent to be used to get laundry clean.
Rinse Cycles and Water Temperature
Fabric Life and Appearance
The Purdue study also found that hard water has a generally negative effect on colors and whites. Colors were found to fade and whites to darken more quickly in hard water. In addition, the study found that laundry washed in hard water became resoiled with greater ease.
Some water utilities offer municipal softening, but water treated in this manner falls short of being soft water. Municipal softening treatment is generally found in areas with extremely hard water, and the end water is still often in the hard to moderately hard range. Municipal softening is also inefficient because all of the community's water is softened, including water that is ultimately used to water lawns and clean public streets. Household water softeners generally provide the most economically effective source of soft water for home and business use.
A typical water softener works on the principal of "cation exchange," in which the ions of hardness minerals (an ion is an electrically charged atom or group of atoms) like calcium and magnesium are exchanged for sodium ions, effectively reducing the concentration of hardness minerals to insignificant levels. As the water enters the softener, it passes over a resin bed in a special tank. The resin is made up of tiny beads of a plastic called styrene linked together by a compound called divinylbenzene. These beads attract and hold sodium or potassium ions. The beads will exchange sodium or potassium for hardness ions such as magnesium or calcium whenever the hardness ions are encountered. The beads are biologically safe, and approved for use by the U.S. Food and Drug Administration (FDA).
After a period of use, the sodium or potassium ions are completely exchanged and the unit has to be "backwashed" or "regenerated," which recharges the resin beads with sodium and potassium ions. This requires the use of sodium or potassium chloride, which is loaded into a "brine tank" where salt dissolves in water, forming the brine which is used to recharge the system. The recharging is most often done in one of two ways. Automatic softeners initiate the regeneration process on a set schedule based to anticipated need; Demand Initiated Regeneration (DIR) softeners use a meter or sensor to monitor the actual hardness levels, or the amount of water a unit has processed, to determine when backwashing is necessary.
Some concerns have been raised as to the presence of sodium ions in the water, especially as a result of water softening. Use of sodium ions does not make the water noticeably salty, nor does it significantly increase a person's sodium intake. For example, a person who drinks eight 12-ounce glasses of water per day softened from 20 gpg hard water takes in less than ten percent of their typical dietary sodium intake from this source. In fact, the FDA defines water that would result from softening 100 gpg hard water (where many more sodium ions would have to be exchanged than is typically the case) as a "low sodium" beverage. This level of sodium should only affect individuals on a significantly restricted diet; anyone who falls into this category should consult their doctor.
Many of softened water's benefits apply to other areas of the home or business. Bathroom and kitchen fixtures stay cleaner without the formation of soap curd, water heaters operate more efficiently and last longer, dishes get cleaner with less detergent and dishwashers last longer, and even bathing is free of hard water deposits which dry skin and dull hair. When it all adds up, hard water is a waste that can be done without.
For more information on the benefits of water softening, contact a Certified Water Specialist (CWS) or Water Quality Association member.