Water softener buying guide

No matter which type of water softener you choose, you'll have to think about the following factors.

Water hardness

Initial water hardness 

Of course, you'll have to start by finding out how hard your water is. If the level of mineral deposits in your water is low (under 100 Parts per Million or PPM), you don't technically need a water softener. Water hardness can easily be measured by a basic water test kit. Alternatively, you can order a more advanced water analysis test from an independent laboratory for more precise measurements of all the elements that can cause hard water.

Soften water or limit limescale

Based on your findings, you might find you need to soften your water or simply try to limit limescale build-up. In the first case, you should look into purchasing a salt-based water softener that works using ion-exchange resin beads. This type of water softener is designed to really reduce the hardness of your water. In the second case, a salt-free water softener should be enough.

Water softener capacity 

Your choice of water softener will therefore depend on your water consumption, the number of people in your home and how hard your water is.

Capacity and volume of resin

The capacity of a salt-based water softener depends on the volume of resin in the tank. You can use the following guidelines when making your choice.

If you choose a salt-free system, you just need to think about your water's PPM rating and the size of your pipes.

Whether you're connected to a mains water supply or have your own source, the quality of your water is strictly regulated. The various standards in place ensure that the water supplied to you is safe for drinking and free from any health risks. But there is one unregulated factor that, while it won't effect the quality of your drinking water, can be harmful for your pipes and your sanitaryware: water hardness!

Water hardness is usually measured in parts per million (PPM) which translates into the concentration of calcium and magnesium contained in water.

100 PPM or less

Water with a PPM rating of 100 or less is generally considered soft (or at least moderately soft). Soft water contains very little calcium carbonate (less than 40 mg / l) and while it does tend to be very corrosive to metals, it won't leave you with limescale.

100 to 200 PPM

Water with a PPM rating of 100 to 200 is slightly to moderately hard. This type of water contains a moderate amount of minerals meaning it isn't too corrosive and won't leave you with a lot of limescale. It will, however, help to provide you with your daily intake of calcium and magnesium.

200 PPM or more

Water with a PPM rating of over 200 is described as hard water. It is not at all corrosive but it will quickly lead to limescale build-up on your sanitary appliances. Typically, this is the point that a water softener is considered a good idea.

The main aim of a water softener is to correct hard water.

Salt-based water softeners 

The calcium and magnesium content of water (i.e. main components in hard water) is regulated through a process of ion exchange. Technically speaking, water softeners work to replace calcium (Ca2+) and magnesium ions (Mg2+) with sodium ions (Na+). Water softeners are equipped with an ion exchange resin through which the water is forced to travel. The resin is charged with sodium by a special water softener salt. The exchange happens when the water travels through the 'brine' created. The exchange capacity will, of course, be limited by the volume of resin and the initial hardnessof the water you want to soften. These water softeners have two different modes. Distribution mode

The resin is charged with sodium and the water softener releases the treated water that is now free of most of its calcium and magnesium ions. This means you now have soft water running through your home.

Regeneration

Once the resin is saturated by calcium and magnesium and has no more sodium ions to exchange, the system has to be regenerated. In this case, the brine tank is used to reverse the resin charge. The brine (mixture of salt and water) travels through the resin and works to clean it and get rid of all the ions that were previously exchanged. This saltwater is then disposed of as waste water. The process of regeneration can last a few hours.

The distribution / regeneration cycle is controlled by a timer that takes a few different factors into account:

• estimated water consumption;

• initial water hardness;

• water softener exchange capacity.

Salt-free water softeners 

These systems work a little differently. Most salt-free water softeners work using electromagnetic energy. They do not get rid of the minerals that cause limescale; instead, they work to change their structure making them less likely to stick to surfaces. Please note, however, that these systems don't actually change the PPM rating of your water! These devices are therefore technically not 'water softeners' as they are simply designed to remove limescale. They are considered to be more environmentally friendly than salt-based systems as they don't contain any hard-to-recycle resins and don't need to be topped up with salt. However, even though they do change the structure of minerals, the minerals that cause limescale are still in the water. A salt-free system only performs one function and requires virtually no cleaning or maintenance. Once set to your water's hardness, these systems work continuously. Some manufacturers claim that salt-free systems can even remove existing limescale but these claims are generally not backed by science.

Maintaining a salt-based water softener

• Twice a year, measure the hardness of your water to check that the settings are still correct and clean the filter inlet and outlet

• Once a year, disinfect the water softener. Generally speaking, this should only consist in pouring a disinfectant solution directly into the tank, leaving it to work and setting up a regeneration cycle.

• Every two to three years, clean out the brine tank (by opening up the drain valve). Once you've finished cleaning, top up the water softener salt and start up a regeneration cycle.

Maintaining a salt-free water softener

Be sure to check that the system is working properly two or three times a year (by looking for limescale in your household appliances, your water heater, and so on). If you want to treat your water at the same time, don't hesitate to add a filter system such as:

• a polyphosphate filter;

• an active carbon filter;

• a sediment filter;

• a cartridge water filter.

Finally, bear in mind filter systems are designed to keep their users healthy and therefore require maintenance to ensure good performance.