Water Treatment FAQ's


1. What is Water? Water is a tasteless, odorless, colorless liquid in its pure state. Pure water seldom exists, but contains gases and solids picked up from various sources.

2. How Does Water Become Contaminated? Water can become contaminated with foreign substances, either by picking up natural impurities in the air and earth or by dumping of sewage or trade wastes into streams, etc.

3. What are the Natural Impurities Picked Up by Water? Natural impurities picked up by water consist chiefly of minerals and gases. The most common minerals present are calcium carbonate, or limestone; magnesium carbonate, or dolomite; calcium sulfate, or gypsum; magnesium sulfate, or Epsom salts; sodium sulfate, or Glauber’s salts; sodium chloride, or common salt; silica, or sand; with minor quantities of iron, aluminum, and others. In the vicinity of mines, water sometimes contains considerable acidity, and in some alkali districts, considerable sodium carbonate, or natural soda ash. The carbonate rarely exists as true carbonate, but rather as bicarbonate, which is a union between the true carbonates, carbon dioxide and water.

4. What Impurities in Water Form Scale in Pipe Lines, Water Heaters, or Boilers? The calcium and magnesium bicarbonates and sulfates, and silica are usually classed as scale forming solids present in water. The carbonates will form scale in pipe lines and water heaters even when temperatures are not very high. Sulfates and silica form scale in boilers. The carbonates do not always form scale but may separate out as a sludge or mud.

5. What Impurities in Water Cause Corrosion? Corrosion is more commonly caused by dissolved gases naturally present in the water supply, namely, carbon dioxide and oxygen. High quantities of sodium chloride and sodium sulfate tend to accelerate corrosion. Waters having a high ratio of chloride and sulfate to alkalinity are usually corrosive.

6. What is High Capacity Softening Resin? Resin is a bead-like plastic or synthetic resin material having ion exchange properties. It is produced from styrene and divinylbenzene and contains sulfonic acid groups. When regenerated with sodium chloride (common salt), it will soften water by exchanging sodium ions for calcium and magnesium ions (hardness). This product, also known as Nalcite HCR**, is widely used as the chemical softening agent in domestic, industrial and municipal water softening equipment.

7. How Does a Softener Remove Hardness from Water? As the water passes through a water softening appliance containing a bed of resin, the hardness (calcium and magnesium) present in the water is exchanged or swapped for sodium in the resin. When the available sodium has all been exchanged for calcium and magnesium, hard water is present in the softener outlet and the resin must be regenerated. Common salt is used to replenish the supply of sodium in the resin and the hardness is flushed to waste.

8. How is Iron Removed from Water? Iron in solution is removed in the same manner as hardness. Oxidized iron, or iron in suspension is filtered from the water by the resin. Some iron which may have been in solution when removed by the resin may become oxidized. This form of iron is more difficult to remove from the mineral bed.

9. How Much Iron will Resin Remove? If all the iron could be kept in solution before softening, and further oxidation is prevented, large amounts of iron could be removed before leakage would occur. The hardness of the water has a bearing on the amount of iron that can be handled, since this controls the gallons softened between regenerations. Generally, the higher the hardness the greater the amount of iron that can be handled. It is sometimes necessary to limit the amount of water softened between regenerations in order to control the total amount of iron introduced to the resin between regenerations. This is often true when softening low hardness waters containing iron.

10. Will the Water Softener Soften Hot Water? Resin is not harmed by hot water. It is widely used in industry at temperatures to 250’F. Not all equipment however, is designed for use with hot water.

11. How Long will Resin Last? Resin in a home water softener should outlast the softener itself. This resin is extremely durable, both chemically and physically. Unless it is unintentionally washed out from the softener, it should seldom need replacing. There are, of course, instances where the resin becomes badly fouled with accumulated suspended material, such as iron, dirt, oil, etc. making it necessary to remove the resin for chemical cleaning or replacement. Resin is not harmed by acids or common solvents although not all acids or solvents can be put into a water softener tank.

12. No Soft Water after Salting; What is Wrong with the Softener? It is probable that something is wrong with the control valves on the softener. Regardless of how badly contaminated the resin may be, some soft water should result after salting.

13. The Capacity of My Softener is Dropping; What can be the Reason? First, the water supply should be tested to make sure that there is no increase in the hardness. Next, the softener should be inspected to see if resin has been lost. Regeneration time should be checked to see if rate controls are functioning properly. The resin should be examined for dirt, iron, etc.

14. How Do I Check to See if the Resin is Dirty? Open the softener after normal backwash. Drain the water down to the bed and scoop out some resin with a spoon or metal cup, taking resin from below the surface. Place some of this in a quart fruit jar (about 1" of resin), half fill with water, and seal. Shake and allow resin to settle from the dirty water, pour off the water into a pan, and repeat until the resin settles in clear water. The resin can then be examined in good light and the amount of dirt removed will give you some idea of the dirt in the water softener.

15. How is Resin Cleaned When it Gets Dirty? Often a thorough backwashing will restore the dirty bed to capacity. If this fails, the bed may be agitated or stirred up using a broomstick, paddle or the like. This loosens up dirt which can then be washed out. In severe cases of iron fouling, the bed should be cleaned with a suitable material such as Nalco Fer-Rid, sodium hydrosulfite, etc. upon instruction by the softener manufacturer.

16. Why Does it Take So Long to Salt and Rinse a Water Softener? The time prescribed by the manufacturer of the softener has been designed to assure maximum capacity of the mineral. Most softeners are salted and rinsed at a slow rate of flow. A fast flush when rinsing is nearly complete will restore soft water more quickly. The salting may be done more rapidly but at a sacrifice of capacity.

17. Why is the Flow Through My Softener Much Less than When Installed?

Check the top screen for hard water plugging. On some water, a larger opening is required to keep flow up. If this is not the reason for the flow restriction, call the serviceman, as the lower distributor may be plugged. Dirty mineral may also cause trouble. See question 14.

18. Will Salt Hurt the Septic Tank? No. The dilution is so great that no difficulty is experienced when the drain from a softener is piped to the septic system.

19. Should a Softener be Sterilized; How Often? A newly installed piece of equipment should be disinfected before use. This can be done with ordinary laundry bleach (liquid), such as Clorox, Linco, Bo Peep, etc. using about 1/2 cup for a 30,000 grain softener and one cup for larger softeners. Direct salting softeners may be disinfected by dumping the bleach into the tank opening, closing the unit and rinsing. Brine tank softeners may be treated by adding the bleach to the brine tank. For sanitary reasons it would be desirable to disinfect direct salting softeners each time the salt is added to the brine tank. With dry salt storage brine tanks, the bleach should be added to the open tube containing the float and the ejector, during the brine draw. When septic tanks follow the softener, bleach will have no damaging effect on the septic tank action.

20. There is an Objectionable Odor in the Water from the Water Softener. Is this Coming from the Resin? The processing and control of resin manufacture is such that the taste or odor should not result with its use. If taste or odor is noticed, sterilizing of the unit will usually correct the condition unless it is caused by sulfides or other non-exchangeable substances present in the raw water.

21. Will a Water Softener Remove Sulfur? There may be some removal or reduction of hydrogen sulfide when a water softener containing resin is first installed. This is only a temporary effect however, due to reaction of sulfide with the resin. It cannot be reproduced by regeneration. An oxidizing filter containing manganese treated greensand or zeolite is required for sulfur removal. Other methods of hydrogen sulfide removal involve chlorination and filtration, or aeration plus chlorination and filtration.

22. Can Soft Water be Used for Cooking and Coffee Making? By all means. Hard water actually reacts with some foods robbing them of taste. Peas are shriveled by hard water, stay round in soft water. Good tasting coffee is more easily prepared when soft water is used.

23. Can Soft Water be Used in a Steam Iron? Soft water contains minerals which will deposit in steam irons as the water is evaporated. Best results are obtained when using distilled water or demineralized water. Other sources of supply are the dehumidifier as well as rain water. However, soft water is preferred to hard water, since the deposits can be dissolved and flushed out, while scale deposited from hard water is more difficult to remove.

**Nalcite and HCR are registered trademarks of Nalco Chemical Company.