Believe it or not, where you live and what type of water you have can have an effect on your home and swimming pool. Let’s take a look at the myths and truths of hard water vs. soft water and discuss some basic chemistry.
What is hard water? Good question. Hard water is simply water that has a high mineral content. This is opposite to soft water which is water with a low mineral content. Hard water usually contains high levels of metal ions like calcium (Ca) and magnesium (Mg). These minerals are in the form of carbonates but could include several other metals as wells as bicarbonates and sulfates.
Hard water does not pose a threat to your family’s safety or health. However, it can be the instigator of costly problems in your home.
Are you unsure if you have hard water or soft water? There is a simple test that can be done right at home to determine if you have hard or soft water. It’s called the lather/froth test. Take some soap and try to lather up your hands. If it easily suds up when agitated, then you have soft water. If it takes some time, you most likely have hard water.
Like previously stated, hard water is not dangerous. It can, however, cause some problems for every day activities like bathing, washing clothes or dishes, shaving, or washing a car. Hard water is not as efficient as soft water because it can cause lime scale deposits in kettles, washing machines, and pipes. Not to mention it will most likely not leave your car sparkling clean after using a hard water hose to wash it. In fact, some say the term ‘hard water’ was coined because it made cleaning difficult.
How does hard water form? When water travels it dissolves, suspends, and exchanges certain trace elements and compounds from anything it comes in contact with. Water hardness is usually measured by the total concentration of calcium and magnesium. These are the two most prevalent divalent metalions. In some areas iron aluminum and maganese can also be present.
There are two types of water hardness. The first is “Temporary Hardness”. The second is “Permanent Hardness”.
Temporary Hardness: This water hardness can be removed by boiling the water or by the addition of lime (calcium hydroxide). It is only caused by a combination of calcium ions and bicarbonate ions in the water. Boiling forms carbonate from the bicarbonate ions and will evaporate the calcium carbonate out of the solution leaving the water less hard when it is cooled. (disclaimer: it should be noted that the previous explanation is an oversimplified version of a very complicated chemical process that occurs).
Permanent Hardness: This type of water is hard water that has mineral content that cannot be removed by boiling. It typically is caused by the presence of calcium and magnesium sulfates in the water. They become more soluble as the temperature rises. It is possible to use a Calcium Scale Reduction System or a Sterling Water Conditioner that will reduce the hard water deposits without the use of chemicals or salts.
Problems caused by hardness in water:
Hard water is not generally unhealthy for you or you family. However, it can cause costly problems. It causes scaling, which is the precipitation of minerals that form a rock-hard deposit called lime scale. Lime scale can clog pipes and can decrease the life of a toilet flushing units by 70% and water taps by 40%. It can sometimes coat the inside of tea kettles or coffee pots and ruin water heaters. All of these issues can require costly replacements.
For homes with hard water, laundry and washing require almost twice the amount of soaps and detergents to do the same cleaning that could be easily done with soft water. Soap scum forms from the combination of hard water and soap and is very difficult to remove. It can form a ring on your bathtub and create unsightly spots on your dishes.
Not only can hard water leave residue on bathtubs and dishes, but it can leave residues on your body as well. Using soap on the body with hard water sometimes causes the formation of a residue often referred to as ‘curd’. This forms when calcium and magnesium form insoluble salts found in soaps. The curd can remain on your skin after rinsing and can clog pores. This issue can lead to bacterial growth, causing rashes, or minor skin irritations that look dry and continually itch.
In the industry setting, hard water contributes to scaling in boilers, cooling towers and other industrial equipment. Water hardness must be constantly monitored in these settings to prevent damage. It is controlled by the addition of chemicals and large-scale softening with zeolite resins.
Water Softening:
Water softeners work by exchanging ions. The ions of the hardness minerals are exchanged for sodium, thus reducing the concentration of hardness minerals to more tolerable levels. The most common way to achieve water softening is with an ion exchange water softener. This water softener uses sodium chloride (table salt) to rechard beads made of ion exchange resin. It exchanges hardess mineral ions for sodium ions. As the water passes through the beads, the hardness mineral ions are absorbed, displacing the sodium ions. This process is known as an ‘ion exchange’, just like the name. When the beads have a low concentration of sodim they can no longer soften the water. The resin is then rechared by flushing with saltwater.
The excess concentration of sodium ions then alter the balance between the ions in solution and the ions being held on the surface of the resin. This results in the replacement of the hardness mineral ions with sodium ions. The resulting saltwater and mineral ion solution is rinsed away, and the resin is ready to start the process once more. This cycle is often repeated many times.
Examining Water in the USA:
In the United States today, 85% of homes have hardness in their water according to the United States Geological Survey. The softest waters can be found in regions like New England, South Atlantic Gulf, and Hawaii. Harder waters are common in the rivers of Tennessee, the Great Lakes, the Pacific Northwest, and Alaska. Very hard waters are found in some of the streams in most of the regions throughout the country.
The hardest waters (more than 1,000 mg/L) are found in streams located in Texas, New Mexico, Kansas, Arizona, and southern California.
Now that we’ve examined hard water vs. soft water, hopefully you will be able to discern which type of water you have and which type(s) of treatment is best for your home and pool!