Water Chemistry--Major Appliances: Operation, Maintenance, Troubleshooting + Repair

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Water is probably the single most important resource that we have on earth. As it falls from the clouds and flows through the earth, water gathers many impurities because of the pollution and the natural minerals in the earth. Most f these impurities must be removed before the water is useful for human consumption. In addition, some of them must be removed before the water will do the job that we would like it to do.


When rainwater falls to the earth, it passes through a polluted atmosphere and picks up some pollutants, usually evaporative chemicals, before it reaches the earth. These airborne chemicals react with the water to form many types of acids. This then becomes what is known as acid rain. When the rainwater drains through the earth, it absorbs more chemicals which cause the chemicals already in the water to become more active.

When people dump their waste into the ground, the waste flows through the earth and enters the aquifer from which we all obtain our water. This waste only adds more minerals and pollutants to the water supply. The result is that nature is no longer in balance.

A good example is the use of laundry and other deter gents that we use to keep ourselves clean. These detergents contain two principle ingredients: a surfactant and a phosphate.

The surfactant (wetting agent) lowers the surface ten ion of the water to improve its penetration into the fabric being cleaned. At one time the major surfactant was ABS alkyl benzene sulfonate). This additive was very slow in breaking down in nature. It caused excessive foaming action in the sewage treatment plants, the lakes, and the streams into which the water containing ABS was discharged. How ever, this surfactant has been replaced with LAS (linear alkylate sulfonate), which is readily biodegradable in nature. Biodegradation is caused by the useful bacteria (commonly found in sewage, surface water, and soil). These bacteria break down the surfactant and use it for food, converting it to water and carbon dioxide. This step brought one form of pollution under control.

The phosphate used in a laundry detergent serves several important purposes:

It increases the efficiency of the biodegradable LAS. The soil particles in the wash water are kept in suspension.

It brings the alkalinity level to the necessary level that is needed for the efficient cleaning of laundry.

Oil and greasy soils are emulsified.

It helps in making the water softer by combining with the hardness minerals.

It aids in the reduction of germs left in the clothes.

Phosphates are effective in laundry detergents, but they don’t decompose in normal septic tanks or sewage treatment plants. Therefore, phosphates appear as sewage effluent in lakes and streams. When combined with other nutrients that are present in lakes and streams, phosphorous provides an excellent nutrient for plant life. In fact, it may be too good because it will sometimes clog the streams and lakes with algae, killing off the fish population.

Only human efforts can control the waste materials and treat them before they enter the earth and the atmosphere so that reasonably clean uncontaminated water is available for our use. Because water has a natural affinity for certain kinds of minerals, it’s necessary to use some type of water-conditioning equipment. Two of the major problems are hardness and iron.

Fgr. 1 Hydrologic or water cycle.


When people refer to hard water they mean that the water contains certain minerals that make it less desirable for use in the home without some form of treatment.

Hard water has the characteristics or the quality that results in making an insoluble sticky curd when it’s mixed with soap. This hardness is caused by calcium and magnesium, carbonates, and sulfates.

The making of hard water---Water as it’s cycled from the clouds in the form of rain to the earth and back to the clouds again is called the hydrologic or water cycle. In this way water is in constant motion, being drawn from the earth in the form of evaporation, stored in the clouds, then released as snow, hail, or rain.

When the water is released from the clouds is just about the only time that the water is in a pure form. This is because during the fall from the clouds to the earth it gathers some impurities in the form of gases, dust, bacteria, smoke, and other forms of pollutants from the air.

Because of this, when the rainwater reaches the earth, it’s already contaminated, to some extent. Then when it contacts the earth, it picks up more contaminants.

The water drawn from a well, or ground water, takes on the characteristics of the earth that it travels through, or percolates, as it flows to the aquifer. As the water falls from the clouds through the air, it absorbs some carbon dioxide and other gases, which serve to increase its solvent effect on the soluble minerals in the soil, rocks, and other mineral formations in the earth.

The quality of the water is, therefore, determined by the amount and kind of dissolved minerals and organic matter gathered by it while passing through the earth to the aquifer. The most common ingredients found in the water are dissolved or suspended matter such as carbonates, chlorides, and sulfates of calcium, magnesium and sodium, and copper, iron, and manganese. Organic matter of vegetable or animal origin and gases may also be dissolved in the water. Also present are suspended solids such as iron, silt, refuse, and organic and animal matter.

Fgr. 2 Soft water rain.

Also, limited amounts of dissolved minerals that are not harmful to the human system may be present. However, in most cases these impurities affect the taste, color, odor, and the general usefulness of the water, usually to such an extent that it must be treated to remove the harmful factors before it can be safely used.

The more common complaints about water are hardness, turbidity, red water, odor, and taste. These may occur individually or in some combination.

The amount of calcium and magnesium in the earth through which the water flows determines just how hard the water will be. The hardness of the water will be different i different parts of the country. In some cases the areas may be smaller than indicated on the map.

Hard-water effects---The minerals that cause hard water seriously affect the efficiency of detergents when they are all combined in water. As a result, a grimy scum forms which causes clothes and other things washed in the washing machine to be dingy and gray looking. It also prevents them from being as soft and white as they would normally ‘e. The plumbing system becomes clogged with this scale preventing the proper drainage of the water. See Fgr. 8—4. Hard water reduces the effect of everything that we use in us homes. Bath soaps don’t clean as they should, shampoos don’t make the hair soft and manageable, and dishes and glassware are streaked and dull, just to name a few of the more noticeable effects. All of these conditions are caused by soap that does not dissolve completely, leaving the residues clinging to the glassware, dishes, and the skin. This residue is extremely difficult to remove if it can be removed at all.

Soaps---Calcium and magnesium salts have harmful effects in washing, whereas sodium salts do not. All three types are mixed with vegetable oil acids to make soap. The sodium soaps are very popular because they are natural agents for washing. However, the calcium and magnesium salts combined with vegetable oil acids form sticky, non- cleaning curds.

When ordinary soaps are used in hard water, an ex change takes place which results in a mixture of hard soaps and soft water. In this manner the initial portion of the soap goes to make the sticky insoluble curd. There is little, or no, suds buildup until all of the minerals that make the water hard are consumed. This is when the curds, or scum, are formed. When clothes are washed in this type of mixture, the curds won’t wash off, leaving the clothes dingy and gray looking.

In addition to this, the rinse water is fresh and contains more minerals that cause hard water. When these minerals combine with the soap lather left in the clothes during the wash cycle, more curds are formed that won’t wash off. The clothes are left with a gray appearance. When soft water is used, there is no adverse reaction with the minerals in the water. The rinsing action merely flushes the lather and dirt down the drain, leaving clean and fresh clothes.

Using soaps in hard water is also expensive. When the hardness of water is increased from 2 to 32 grains of hardness, the soap consumption doubles for the same washing loads. This is in addition to the unpleasant side effects of skin irritation, stiff clothing, poor tasting drinks, and costly damage to the plumbing system.

Testing for hardness---Hardness is measured in grains per gallon of water. A grain is a measure of weight of the scale-forming solids in the water. People who have had water softeners installed can often determine whether the water is soft or hard just by feeling it. One of the more common methods used to determine whether or not water is hard is to simply taste it. A more scientific way is to use one of the many test kits that are available for testing the hardness, iron, pH (acidity), and/or other impurities that may be in a specific area. Of major concern to the appliance technician is the amount of hardness in the water. This can be determined by a test known as the green soap test.

One of the methods used for this is to measure an ounce of the water into a clean glass jar. Then add tincture of green soap, shaking the glass of water after adding each drop. Continue to add the drops, one at a time and shaking after each drop, keeping track of the number of drops added to the water. Do this until suds are formed on the water.

Zero soft water requires only one drop of green soap per ounce to form suds. On the other end of the scale, hard water requires one drop of green soap per ounce of water for each grain of hardness before suds are produced. If the water sample should require 15 drops of green soap per ounce, the water would have 15 grains of hardness.

Water needs---When a water softener has been in stalled and the household repeatedly runs out of soft water, the needs of the household should be checked against the capacity of the water softener. There are several factors that could cause this problem. For example, a family may have outgrown the capacity of the softener, or the water in the area may have become more hard since the water softener was installed.

On average, each person in a family uses 50 gallons of water per day. To determine the number of grains that must be removed from the water each day, multiply the number of people in the family limes 50. Then multiply the answer by the grains of hardness of the water.

Fgr. 3 Water hardness map of the United States.

For example, a family of five using water with a 15 grain hardness would require: 5 x 50 x 15 = 3750 grains of hardness to be removed each day just to satisfy the mini mum needs of the household. Then dividing this Fgr. into the capacity of the water softener will indicate how long the water softener can go between generations.

In our example the water softener has a capacity of 15,000 grains; then 15,000/3750 = 4 days between generations.

Ion exchange One method of controlling the water hardness for domestic use is with an ion-exchange water conditioner.

Basically, this type of unit consists of a tank containing resin beads that are loaded with sodium ions. These resin beads prefer calcium and magnesium ions. Because of this, as the water flows through this tank of beads, the sodium ions are given up and the beads collect the calcium and magnesium ions from the minerals in the water.

The minerals that are left don’t have a negative reaction with the soaps and detergents that the calcium and magnesium ions do. Also, they don’t leave any deposits in the water pipes.

As the water is used, the resin beads will have given up all of their sodium ions and the unit will need regeneration. Regeneration is accomplished by flushing a brine solution through the resin beads, removing all of the calcium and magnesium ions. The sodium ions then take their place on the beads. The flushed calcium and magnesium ions are washed down the drain. The resin is then washed with fresh water and the unit will again supply more soft water.

There is no wear or loss of the resin pellets during the regeneration process. The only requirement is that the user replenish the unit periodically with salt for the regeneration process.

Only salt that is recommended specifically for this purpose should be used. This is because all of the impurities settle in the bottom of the salt tank and must be cleaned out periodically.


The following list will help clarify some of the questions about water softeners and the use of soft water:

1. Clothes will require several washings before the gray dull color and the curds have disappeared.

2. The first several tanks of hot water will be hard. Then the remaining tanks will be soft.

3. Rinse water from a water softener won’t harm a septic tank.

4. Outdoor plants and lawns should not be watered with softened water because: (1) it’s expensive and (2) over a long period of use, the excess sodium ions will unbalance the soil composition.

5. House plants can be watered with soft water if care is taken to completely saturate and flush the water

Fgr. 4 Fuel loss from scale. through the soil each time and not water too frequently. Some types of house plants are not affected; others are affected to some extent.

6. In a well-maintained, balanced aquarium in which water is added only to replenish any loss by evaporation, soft water can be added slowly as required and the fish won’t be bothered, because the dilution ratio is so small.

7. In the first washing with softened water, decrease the amount of soap or detergent generally used to one- third or one-quarter of that previously used. On subsequent washings, add or decrease as required to obtain sufficient suds.

8. The rust and scale accumulation in the plumbing will be loosened by the soft water. Be prepared for occasional “slugs” of rusty water until the entire system has been cleared.

9. Soft water should not be used in car batteries. Use only distilled water.

10. Other filters and water-conditioning equipment must be installed in the line between the pressure tank and the softener, as needed.

11. Some people don’t like the taste of softened water and others, under doctor’s orders, on a low-sodium diet, must not drink softened water. For these reasons, many installations include one tap from the unsoftened source.


Fgr. 8—5 Water softener connections for iron removal. MAIN WATER SUPPLY




Red water generally contains excessive amounts of iron. There will be red stains on the plumbing fixtures and on the laundry. The taste will generally be changed and the appearance of tea, coffee, and other drinks will often be changed.

The red color is because of the iron hydroxide present in the water. Sometimes the water will appear to be clear when drawn, but it will redden after coming into contact with the air because the soluble iron changes to insoluble iron. The insoluble iron is what causes the problems.

There are two ways to control the amount of iron in the water for domestic use. The type of method used depends on the amount of iron involved. An ion-exchange water softener can handle small amounts of iron very effectively. However, large amounts—more than 3 to 5 parts per million—of iron must be removed by special iron filters.

There are no general recommendations for the treatment of iron in the water because of the complex makeup of this component. Each situation is different and requires that specific consideration be given each application. It must be remembered, however, that the iron filter must be in stalled between the water source and the water softener. This location is necessary to protect the resin in the water softener from iron fouling. When the resin becomes iron-fouled, it will no longer soften the water.

There a few steps that can be taken to keep the resin from becoming iron-fouled when small quantities of iron are present. One is to prevent the water from coming in contact with air (oxygen) before entering the water softener. This is done by placing an air cell, such as an inflated bag or balloon, in the pressure tank.

Another effective method of accomplishing this is to periodically introduce some sodium hydrosulfite into the brine. This will help to clear the ferric hydroxide from the resin beads, allowing them to perform their function in a normal manner. When the resin beads become badly fouled, it may take several successive treatments to remove all of the iron. When it’s finally cleared, the water softener should perform well with only periodic, preventative treatments. A good treatment is 2 to 4 ounces of sodium hydrosulfite for each cubic foot of resin bed. Therefore, a 15,000 grain softener (having 14 cubic feet of resin) would require only 1 to 2 ounces. To treat the softener, pour the compound into the brine tank every time a 100-pound bag of salt is added.

These iron-reducing chemicals are available under a variety of different brand names: Lykopon, Fer-red, Iron out, and Rover are some of the more common brands avail able. These products can usually be purchased at the store that sells the water softener salt.


There are usually other undesirable impurities in natural water. They can be noticed in several different ways, such as taste, color, and odor. These impurities are usually present in a lesser degree than those described above. There is usually someone available who can assist in treating these impurities properly. In most instances the superintendent of the local water company would be the one to start with for help.


1. What is probably the most important resource on earth?

2. What causes acid rain?

3. What is used to lower the surface tension of water?

4. What causes biodegradation?

5. What, in a laundry detergent, aids in the reduction of germs left in the clothes?

6. What do calcium and magnesium, carbonates and sulfate cause?

7. What determines the quality of water?

8. What affect does hard water have on clothes washed in it?

9. Will soap build-up suds in hard water?

10. How is the hardness of water measured?

11. On the average, how much water does each per son use daily?

12. What does the user of a water softener need to do periodically?

13. What does red water generally contain in excessive amounts?

14. Where must an iron filter be installed?

15. In most instances, where is the best place to start to solve water problems?


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