How Does A Water Softener Work — Water Softener Systems for Hard Water

TopProducts may earn commissions from affiliate links on this page. Not only does this help us maintain our website, but it also helps support our scholarship program. Learn More.

Picture this, you want to do laundry, but mixing soap with water produces scum instead of foam. Using water that does not mix well with soap is one of the major effects of hard water.

When there is hard water, soap doesn’t work as well. But that’s not all, it can have a negative impact on your hair and skin, as well as your home appliances.

Hard water is a result of excess calcium or magnesium that is picked up along the waterways before the water gets to your property.  It’s common in homes with well water.

Although hard water is considered healthy for drinking because of the ions contained in it, it is a different story when it comes to house chores like laundry and dishes. Clothes come out looking dingy, and dishes will have spots, making it look like they were not rinsed well.

Soap becomes less effective in hard water because it reacts with the calcium and magnesium, causing it to form scum instead of lathering well, hence the introduction of a water softener. If you have hard water, you are going to need more than just a water purifier or water filter, because neither of those by themselves will fix the problem.

In this article we will be talking about water softener devices which are used to treat hard water. They can be whole house water softener systems, or smaller units attached under a sink or to a shower. There are also systems which do two jobs — soften water and filter out contaminents. 

Related: Shower Head Filters to Reduce Chlorine, Contaminants and Hard Water

What is a Water Softener?

To make work easier around the home or business premise, you can employ the use of a water softener, to transform your hard water to soft. Also known as a water conditioner, a water softener helps in the process of filtration, to remove the presence of calcium and magnesium in the water that causes it to be hard and challenging to use. Water is usually allowed through a filter which sieves out the minerals that make water hard.

Hard water clogs pipes leading to eventual damage that is why it is important to soften your water once you realize it is hard water.

So how do you know that your water is hard? There are test strips that can identify the exact hardness level of your water or you can do the “soap test” using non-detergent castile soap, but there are also some signs to be on the look out for.

Video: Using Soap to Test for Hard Water

How to Test Water Hardness with Pure Castille Soap. | Courtesy of Lisa Bronner

You may not tell by just looking at the water that it is hard, but you can tell it is hard when you start using it. Some of the features of hard water include: 

  • When you mix soap with water, you expect to get a foamy solution, but you will see scum; water divided with the soap you applied. Water that has a high concentration of chemicals breaks down the soap instead of mixing it with the water.
  • You will notice mineral crust forming around the faucet or your water outlet.
  • Your dishes will have stains that look like they were not well rinsed.
  • You realize you are consuming a lot of energy, especially when you use cleaning appliances like a dishwasher and a washing machine for your laundry.
  • In extreme cases, after using the water, you may end up with sensitive skin that is scaly and itchy. Also, your hair will be dry and prone to breakage.

Softening your water only means increasing the lifespan of your appliances and other applications that depend on water to function. In the process, it makes work easier for you. 

How a Water Softener System Works

Identifying the hardness of water is one thing, and softening it is yet another entire process. A water softener is an appliance that you can use around your home to remove chemicals from your water. Hearing about a water softener for the first time, you may be mistaken to think it is a small liquid you pour in water and after a while the water becomes soft.

On the contrary, a water softener system is an actual appliance fixed on the plumbing system of your home, in a way that piped water can pass through it and filter out the unwanted chemicals. The chemicals that make the water hard are often removed and placed with another one (sodium) before being transmitted into your home for daily use. This whole process is known as ion exchange ~ exchanging the good ion for the unwanted ones.

The hard water is directed into a tank called mineral tank filled with resin beads, which are made from polystyrene. Since the beads have a negative charge and the chemicals in the hard water have a positive charge, as the water passes through the mineral tank, the negative charge in the beads gets attracted to the positive charge in calcium and magnesium. The resin beads hold onto calcium and magnesium and in the process releases sodium which is good ion for use. The resin beads take away the hardness in the water leaving soft water to flow out through your faucets. The process is fast and efficient.

Video: Aquasure Harmony Series Whole House Water Softener

Aquasure Harmony Series Water Softener provides soft, scale, and spot-free water for the entire house.

Components of a Water Softener System

A water conditioning system has three main components: mineral tank, control valve and brine tank.

Mineral Tank

A mineral tank is where all the softening of the hard water happens. The water supply sends water into this tank, which is filled with resin beads – the components responsible for stripping the water of its hardness. Once calcium and magnesium are removed from the water, it seeps out through pipes and other outlets into your home.


Also known as the control valve, this valve regulates the amount of water that passes through the mineral tank for ‘purification’ before it is directed to your property. It has a meter that regulates the volume of water that comes into the tank and also, it regenerates the mineral content in the resin beads. After a significant period of transforming the hard water into soft water, the minerals in the beads tend to run out. The control valve starts on a regeneration process to ensure the process of softening water is effective.

Brine Tank

Remember the regeneration process of the resin beads in the mineral tank? Well, the brine tank aids this process. It is often placed next to the mineral tank, and it holds a high concentration of salt, also known as sodium and sometimes potassium –  agents responsible for the softening of hard water. The salt in this tank, which comes in pellets, is added manually, and they dissolve into the water. The moment the regulator signals that chemicals in the resin beads are diminishing, automatically the sodium solution in the brine tank is deposited into the mineral tank. When the brine tank runs out of salt, then the water will not be softened. That is a clear signal that the brine tank needs a refill of salt.

The quality of water you get depends on where you live and where you get your water. A build-up of minerals like calcium and magnesium, limestone and metals like iron are the leading causes of hard water. A water softener is a savior in such a scenario, transforming your water and making it easy to use while also being kind to your energy consumption and the appliances you use.

If you are not sure whether you have hard water, we recommend the H2O OK Plus Complete Water Analysis Kit. For under $30 you can not only test for hardness, but also the levels of chlorine, iron, pH, alkalinity, copper, bacteria, nitrates, hydrogen sulfide and pesticides in your water. 

Video: How to Install a Whole-House Water Softener

Heating expert Richard Trethewey shows how to install water softener system. | Courtesy of This Old House