Hard water is water that has a high mineral content (water with a low mineral content is known as soft water). This content usually consists of high levels of metal ions, mainly calcium (Ca) and magnesium (Mg) in the form of carbonates, but may include several other metals as well as bicarbonates and sulfates. While it is not generally dangerous to safety or health, it does generally cause potentially costly nuisance problems in the home and in industry.
The simplest way to determine if water is hard or soft is the lather/froth test. If the water is very soft, soap will tend to lather up easily when agitated, whereas water that is hard will not. Toothpaste will also not froth well in water that is hard. For many uses, including drinking (aside from the taste), it does not matter whether water is hard or soft. For instance, to put out fires, water a lawn, or wash the mud off the streets, water would have to be very hard to cause a problem. But for bathing, washing dishes and clothes, shaving, washing a car, and many other uses of water, Hard Water is not as efficient or convenient as soft water.
Hardness in water can cause limescale deposits in kettles, washing machines, and pipes. Earlier generations coined the phrase 'hard water' because it made cleaning difficult.
Hardness is caused by compounds of calcium and magnesium. All freshwater sources contain calcium and magnesium in varying quantities. Water dissolves, suspends, and/or exchanges certain trace elements and compounds from many things that it contacts on its travels. Water hardness usually measures the total concentration of Calcium and Magnesium, the two most prevalent divalent metal ions, although, in some geographical locations, iron, aluminum, and manganese may also be present at elevated levels. The deposit of calcium carbonate (also called lime, limescale, etc.) left after hard water has evaporated from a surface is often referred to as 'hard water' even though no water is present.
Types of water hardness: A common distinction is made between 'temporary' and 'permanent' hardness. there are also common types of hardness in water depending on the ion found in the water.
Temporary hardness: Temporary hardness is a hardness that can be removed by boiling or by the addition of lime (calcium hydroxide). It is caused by a combination of calcium ions and bicarbonate ions in the water. Boiling, which promotes the formation of carbonate from the bicarbonate, will precipitate calcium carbonate out of solution, leaving water that is less hard on cooling. It should be noted that the above explanation is an oversimplification of the process that is occurring. The following equilibrium reaction actually happens when calcium carbonate is "dissolved" in water.
Permanent hardness: Permanent hardness is hardness (mineral content) that cannot be removed by boiling. It is usually caused by the presence of calcium and magnesium sulfates and/or chlorides in the water, which become more soluble as the temperature rises. The use of a Hard Water Filter or a Hard Water Bullet will reduce the hard water deposits and make clean up much easier without the use of chemicals or salt.
Problems caused by hardness in water: While hard water is not generally unhealthy (see below), it can cause many potentially costly problems. Hard water causes scaling, which is the precipitation of minerals to form a rock-hard deposit called limescale. Scale can clog pipes and can decrease the life of toilet flushing units by 70% and water taps by 40%. It can coat the inside of tea and coffee pots, and clog and ruin water heaters. In the home environment, hard water requires more soap and synthetic detergents for laundry and washing. It takes half as much soap for cleaning with conditioned water. Hard water and soap combine to form "soap scum" that can't be rinsed off, forming a “bathtub ring” on all surfaces, and it dries leaving unsightly spots on dishes. Using soap on the body in hard water can cause the formation of a scum often referred to as “curd.” The formation of scum and curd is caused when calcium and magnesium form insoluble salts found in soaps. This curd remains on the skin even after rinsing, clogging pores, and coating the body. This can serve as a medium for bacterial growth, causing nappy rash, minor skin irritation, and skin that looks dry and continually itches. Similarly, the insoluble salts that get left behind from using regular shampoo in hard water tend to leave hair rougher and harder to untangle. In industry, hard water contributes to scaling in boilers, cooling towers, and other industrial equipment. In these industrial settings, water hardness must be constantly monitored to avoid costly breakdowns. Hardness is controlled by the addition of chemicals and by large-scale softening with zeolite resins. Hard Water is calcium.
Softening: A water softener works on the principle of an ion exchange in which ions of the hardness minerals are exchanged for sodium, effectively reducing the concentration of hardness minerals to tolerable levels. The most common way to condition and treat household water (I'm clearly not saying the best...)is with an ion exchange water softener. This unit uses sodium chloride (table salt) to recharge beads made of ion exchange resin that exchange hardness mineral ions for sodium ions. Artificial or natural zeolites can also be used. As the water passes through and around the beads, the hardness mineral ions are preferentially absorbed, displacing the sodium ions. This process is called ion exchange. When the bead or sodium zeolite has a low concentration of sodium ions left, it is exhausted, and can no longer soften water. The resin is recharged by flushing (often back-flushing) with saltwater. The high excess concentration of sodium ions alters the equilibrium between the ions in solution and the ions held on the surface of the resin, resulting in the replacement of the hardness mineral ions on the resin or zeolite with sodium ions. The resulting salt water and mineral ion solution are then rinsed away, and the resin is ready to start the process all over again. This cycle can be repeated many times. One problem here is that water softeners are being banned in some large cities because of the pollution they create, and more are expected to follow suit. Read this report about why Water softeners are being banned in several large cities in the USA.
Water hardness in the USA: According to the United States Geological Survey, 85% of US homes have hardness in their water. The softest waters occur in parts of the New England, South Atlantic-Gulf, Pacific Northwest, and Hawaii regions. Moderately harder waters are common in many of the rivers of the Tennessee, Great Lakes, Pacific Northwest, and Alaska regions. Hard and very hard waters are found in some of the streams in most of the regions throughout the country. The hardest waters (greater than 1,000 mg/L) are in streams in Texas, New Mexico, Kansas, Arizona, and southern California. We believe that you will find that Salt-Free Water Conditioners are a better choice and much better solution to solving your water problems, and we know that after you do your research, you will think so too.