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Water Softening > Product Basics
  Hard Water
  Softener Types
  Key Technology
A water softener is an appliance which removes minerals from the water that is piped into your home via the general municipal system in your area. By passing the water through a set of specialized tanks before it can reach its ultimate destination, a water softener delivers materially more pure and effectively "softened" water to the various taps, faucets, shower heads, and appliances within your home.
Hard Water
The majority of the water that is piped into residential homes in North America is in a state known as "hard water". This means that this water has a high proportion of minerals, especially calcium and magnesium. The presence of these minerals, or the "hardness" of the water, leads to a range of negative effects on your plumbing and your appliances

The water flowing through the plumbing inside your home contains more than just plain old H20. Typically, it also contains a certain proportion of minerals, including calcium, magnesium, iron, lead, sulfur, and limestone. Over time, these minerals have a tendendy to build up on various surfaces and in sufficiently large quantities to produce a spectrum of negative impacts.

The full list of known issues resulting from hard water is substantial. Hard water leads to the build-up of scale deposits on the internal surfaces of water pipes, which leads to plumbing clogs. Hard water also damages water-using home appliances, such as washing machines, water heaters, dishwashers, and kettles. Hard water causes water spots on pots, pans, and dishes. It leads to white scaly deposits on showers and sinks. It results in soap scum on bathroom tiles. There is no question that over time hard water leads to a substantial amount of avoidable wear and tear, clean-up effort, and associated dollar expenditures.

The good news is that buying and installing a water softener in your home can help you avoid this laundry list of problems. When your water is softened, you will require less soap and shampoo for washing and less detergent to get your laundry clean. When you shower, your hair and skin will feel softer, cleaner, and less dry. You will not need as much dishwasher fluid and your dishes will clean easier and come out spot free. There will be no more of that soap scum build up on your tiles. Importantly, the operational life of your water pipes and plumbing fixtures will be substantially extended. All of your water-based appliances will work better, faster, and longer. Your clothes will be cleaner and brighter after each wash, the fabrics will last longer, and the colors will not fade as quickly.

While the water entering most homes has a fairly high hardness rating, this is not necessarily the case for your particular area. You can determine the hardness level of the water in your home by either using a do-it-yourself (DIY) test kit or hiring a local professional. There are actually multiple possible measurements which are used to determine the hardness of water. The ones used most often are parts per million (PPM) or grains per gallon (GPG). The PPM value measures the milligrams of calcium carbonate (or equivalent hard mineral, such as magnesium) in a liter of water. The GPG value measures the number of grains (each "grain" is 64.8 milligrams) of a particular mineral in a gallon of water. To convert from PPM to GPG, all you have to do is divide by 17.1. Similarly, to convert from GPG to PPM, all you have to do is multiply by 17.1.

The general rule of thumb is as follows: if the hardness level of your water is 50 PPM / 3 GPG, or higher, then you will experience measurable benefits by putting in a water softener.

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Softener Types
The majority of water softeners use a system of ion exchange. Over the course of time, the components which bind and remove the hard minerals from the water actually become saturated. When this happens, these components have to be regenerated. This regeneration can occur by one of three methods. Consequently, ion exchange water softeners are classified by the method which they use for regeneration. Aside from ion exchange based water softeners, there are also units which utilize magnetic, electronic, and reverse osmosis technologies.

The idea behind ion exchange is actually straightforward and basically involves replacing ions in the water that you do not want - the hard minerals - with ions that do not cause hardness. That is to say, ion exchange involves switching out the mineral ions in hard water with another set of ions. The way this is done is by using a specialized ion exchange material located inside the water softener. This material attracts the hard mineral ions in the water. When these hard mineral ions come in contact with the specialized material, they displace other ions which flow from the material into the water. Over time, the ion exchange material becomes saturated with hard mineral ions. When this happens, it has to be regenerated, which is really just a fancy way of saying that all those hard mineral ions have to be flushed out. With that in mind, let's look at the different types of regeneration which are possible.

A meter regenerated water softener tracks the volume of water which has flowed through the softener and will automatically regenerate once a particular volume of water has been softened. This is an efficient way to regenerate because it is based on the actual demand for water in the household. As a result, the meter regenerated unit is the most popular type of water softener on the market.

A timer regenerated water softener, also referred to as an automatic water softener, works a little differently. Rather than tracking the volume of water, it simply regenerates based on a set time schedule. For example, it might regenerate every 8 hours, or every 12 hours. This works just fine for households where water usage remains more or less steady from day to day. However, for situations where water usage varied considerably day to day and week to week, this can be highly inefficient. In the course of days when the water demand is limited, such as when residents are away, the water softener will regenerate even though it does not need to do so. By the same token, in the course of days when the water demand is far higher than usual, the water softener will not regenerate with sufficient frequency to keep up with the demand.

Finally, a manually regenerated water softener actually requires you to externally initiate the regeneration process. Depending on the model, some of the subsequent functions, including backwash, brining, rinsing and return to service may either be automated, or also require manual initiation.

Ion exchange water softeners, regardless of regeneration type, are a proven technology. By contrast, a new technology is water softeners based on electronic and magnetic interactions. The idea behind these product is that rather than chemically softening the water, they rather make hard water behave like soft water through magnetic fields or vibrations. The true efficacy of such water softeners remains in doubt. Some experts have categorically stated that this technology is ineffective. If you are interested, you should conduct your own independent research and draw your own conclusions. However, our view at present is that this type of water softener is a gimmick.

Another alternative which has been proposed is reverse osmosis filtration. This technology is not intended to specifically soften water, but more generally to rid it of impurities. However, in the course of the filtration process, many hard minerals are also removed, rendering the water softer. Unfortunately, reverse osmosis filtration is a rather costly process when extended to an entire house and may also require the replacement of piping. If the goal is to soften the water in a home, a reverse osmosis system is not the most cost-effective solution.

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Key Technology
As we have explained, the primary technology employed by most water softeners on the market today is based on a system of ion exchange which works by directly removing hard minerals from the water and replacing them with other ions. The actual switch is accomplished via a multi-step process.

The specific elements which result in hard water are, for the most part, calcium and magnesium. When hard water flows through a water softening system, the calcium and magnesium ions are exposed to a bed of resins, which are bascially plastic beads coated with a highly concentrated solution of either potassium or salt. Because the plastic beads are negatively charged, they attract and bind the calcium and magnesium ions, which are positively charged. In turn, the calcium and magnesium ions displace the potassium or salt ions from the beads.

Thus, the hard minerals in the water are replaced with potassium or salt, neither of which has a hardening effect on the water. After the water passes through the water softening system, its calcium and magnesium content is significantly diminished. This transformation results in the water going from hard to soft.


Most water softeners utilize a two-tank system which is made up of a mineral tank and a brine tank. The mineral tank contains the plastic beads - this is where the hard water passes and is softened. However, over time, the salt or potassium on the plastic beads becomes progressively used up and the plastic beads are no longer able to capture calcium and magnesium ions in the water as it passes through. When this happens, the mineral tank has to be regenerated, as mentioned above.

Regeneration is actually a three-part process. The first part is "backwash", when the water flow is reversed and the mineral tank is flushed of all of the accumulated calcium, magnesium and other debris. The second part is "recharge", when new salt or potassium solution is pumped from the brine tank into the mineral tank, refreshing the plastic beads. The final part is "rinse", when the water flow is turned back to normal and the mineral tank returns to exchanging calcium and magnesium ions from the water for salt or potassium ions from the plastic beads.

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