What Is Hard Water and How Can It Be Treated?
Hard water is water that contains certain dissolved chemical that act on soap to form a scum. If water comes from limestone areas, some rock is dissolved in the water, and this makes it hard. There are several disadvantages in hard water. More soap or soap powder must be used to obtain a suitable lather. Also, the scum clings to the object being washed.
Hard water leaves a scaly deposit in kettles and boilers, which reduces the efficiency of both. But hard water can be treated to remove the unwanted chemicals. In the home small amounts of washing soda or borax can be added. At large water softening plants which serve a community, the water is filtered through a mineral called zeolite which removes the chemicals. After a time zeolite ceases to be effective, but it can be restored by washing it with salt water.
Hard water is a result of the dissolved minerals calcium, magnesium and manganese. With an increase in these minerals, the following are seen:
- Soap scum in sinks and bathtubs
- Bathtub rings
- Spots on dishes or shower doors
- Reduced foaming and cleaning abilities of soaps and detergents
- Dingy and yellowed clothes with soapy residues that require extra rinsing to remove
- Clogged pipes from buildup of minerals
- Increased water heating costs from buildup of minerals, reducing efficiency of water heaters
- Possible skin infections from bacteria trapped in pores underneath soap scum
While these are all unpleasant effects, hard water is not a hazard to human health and can be treated. If you suspect that you have hard water, it can be tested. If you are connected to a public supply, call your water superintendent or city hall and ask if the water is hard. If you are on a private supply, collect a sample in an approved container and take it to a testing lab or send to your city or state health department for testing.
Water is considered hard when it exceeds 3 grains per gallon (GPG). A GPG is equivalent to 17.1 PPM, so if your water is 171 PPM, then your hardness is 10 GPG.
When results are returned to you and your water is found to be hard, there are a few options available to you. The most common way to soften water is through an ion exchange water softener. This system works by exchanging positively charged hardness minerals (calcium and magnesium) with positively charged softness minerals (sodium or potassium) on a resin surface that is regenerated. This exchange of minerals softens the water and can extend the life of plumbing systems since there is reduced clogging in the pipes. Residues, including soap scum and spotty dishes, should also diminish.
There are currently three basic types of ion transfer softeners. The first is an automatic softener. This type of softener is connected to a clock timer which at certain time intervals begins the regeneration process by flushing out the hard ions stuck to the resin and replacing them with the soft ions. This then allows for a continuous exchange of hard and soft ions throughout the day.
The second type of softener is the demand initiated regeneration (DIR). With this system, regeneration occurs only when soft water has run out. Since this system adjusts to the amount of water used as opposed to the automatic type, it uses less salt and water and is more efficient. The final softener is a portable exchange. Here a tank is rented to the homeowner and has a regenerated resin. When the resin can no longer exchange ions, the tank is returned to the company and regenerated there.
To choose a system that will fit your needs, it is best to have representatives from different companies inspect your plumbing and give you an estimate. Next, ask your neighbors which companies they use and if they have any problems with their service.
The CDC recommends limiting daily total sodium intake to 2,300 mg per day, though the average American consumes 3,500 mg per day. Because the amount of sodium present in drinking water—even after softening—does not represent a significant percentage of a person’s daily sodium intake, the EPA considers sodium in drinking water to be unlikely to cause adverse health effects.
For those who are on sodium-restricted diets, the use of a reverse osmosis system for drinking water and cooking water will remove sodium along with any other impurities which may be present. Potassium chloride can also be used as a regenerant instead of sodium chloride, although it is more costly. For people with impaired kidney function, however, elevated potassium levels, or hyperkalemia, can lead to complications such as cardiac arrhythmia.
Compared to reverse osmosis and distilled methods of producing soft water, hard water conveys some benefits to health by reducing the solubility of potentially toxic metal ions such as lead and copper, which are more soluble in soft water than in hard water.