How a Water Softener Works from Reddit: (Simple Guide)

Have you ever asked yourself, what is a water softener, why water softener? Or maybe wondered how a water softener works? A water softener is a water filtration system that consists of a tall, narrow tank, and a short, wide brine tank a main valve that connects the appliance to your home plumbing system, and a bypass valve that you can use to do maintenance checks without turning off your home’s water supply. The unit also features control panels and timers.

It softens water by removing mineral ions such as calcium, magnesium, and iron from hard water through a process termed as ion exchange.

But what is hard water? Well, hard water refers to water that contains excessive amounts of calcium, magnesium, and other mineral ions. These mineral ions can cause damage to your home appliances, plumbing system and fixtures. They can lead to clogged up drains, cause soap scum on utensils, and stiff laundry just to mention a few.

Due to these reasons, more and more people are starting to discover the purpose of the installing a water softener in their houses and condos.

But how does a water softener work? Well, in this article we’ll give you a whole in-depth operation of this amazing system. With a good water softener system in place, you can be certain that your hard water problem is solved. Hence water delivered to you is safe for consumption.

How a Water Softener Works


Water softeners operate on the principle of ion exchange where simply the calcium and magnesium ions are replaced with sodium and potassium ions. This process occurs in the resin tank full of small polystyrene beads also called salt or resin beads.

The resin beads resemble a highly porous skeletal structure and each bead varies in size from 0.3 to 1.2mm, containing about 45% moisture. They are composed of polystyrene and divinylbenzene (DVB).

During the ion exchange process, hard water is made to pass through a resin tank that is full of resin beads where an exchange process takes place. The calcium and magnesium ions present in hard water are replaced with sodium ions, which are positively charged.

When hard water passes through resin beads, the calcium and magnesium ions are absorbed from the water and the sodium or potassium ions are released into your water. The ion exchange will eventually reach its maximum after gallons of hard water has passed through the zeolite beads in the resin tank.

Water hardness in the industry is measured in terms of grains per gallon (GPG) or milligrams per liter (mg/L). A grain is defined as 64.8 milligrams of calcium carbonate. If water tests at 1 GPG (17.1 mg/L) or less, it is considered soft water.

If the water is around 1-3. 5 GPG (17.1-60 mg/L) it’s between soft and slightly hard water and water that’s between 3. 5-7 GPG (60-120 mg/L) is considered moderately hard. Water with a concentration of 7-10. 5 GPG (120-180 mg/L) is considered hard water.

When it has reached the maximum, the regeneration process follows. Below is a step-by-step guide of the regeneration cycle.

Water Softener Regeneration Cycle


Backwash Cycle

The first step in the regeneration cycle is the backwash cycle. In this initial step, the valve that supplies waters to your house closes and the reverses the flow of water.

This redirects the water flow to the collector and plumps up the beads in the resin tank. Here water is filtered to get rid of other contaminants which might be present apart from the hard ions.

Brine Draw Cycle

The second step of the regeneration cycle is the brine draw cycle. In this cycle, the valve stays above and the brine valve opens which then allows the liquid to be pushed to the top of the tank.

Brine flows through the resin beads making the calcium and magnesium ions be exchanged of the brine in the salt solutions. The salt solution that contains sodium ions is then collected in the resin bed. This cycle continues until the liquid in the brine tank has been completely.

Fast Rinse Cycle

The cyclical motion is then sped up as the water is given a good final rinse as it flows from the top to the bottom of the resin tank. The high speed of water flow causes the calcium and magnesium to compact at the bottom of the resin as the water undergoes a thorough rinsing to remove all remaining traces of brine and calcium and magnesium ions. 

Service Mode Cycle

The fifth step of the regeneration cycle is service mode. Here is water passing through a valve at the top of the resin tank and then the water flows to the bottom of the collector of the tank that contains resin. When the water flows through the resin, the exchange of mineral ions takes place. 

After this process, the drain valve closes and the service valve opens back up and allows the softened water to pass through slots and the valve pushes water to your plumping pipes that eventually supply water to your home.

Refill Cycle

 The final step of the regeneration cycle is the refill cycle. In this step, you refill the brine tank with water. After the tank is refilled with water and the correct amount of salt, the cycle begins again from the first step.

In most cases, a water softener will use approximately 25 gallons of water to go through a full regeneration cycle. It requires approximately two bags of common table salt for a water softener to soften at least 25GPG of hard water in one month.

Usually, during the regeneration process, there is no supply of soft water, that’s why it’s always advisable to set up your water softener to regenerate at around 2.00 AM when the need for water is minimal or even none in some cases.

This will ensure that your water softener will go through the regeneration cycle uninterrupted. However, still, there’ll be soft water supply to the house via the bypass valve.

Though not all models use this regeneration mechanism, in most cases, this is how most water softeners operate.

In some instances, you’ll find models that have the brine and resin tank separately and others come as a combined unit. It doesn’t matter anyway as both models will deliver the same result. Most people nonetheless will prefer the combined unit to separate one since it doesn’t occupy a large space.

Also, it’s important to note that potassium chloride is another possible softening agent apart from sodium chloride. Individuals with underlying health conditions such as heart and kidney problems will go for potassium chloride as a softening agent instead of sodium. 

One drawback though is that potassium chloride is a bit costly as compared to common table salt. Another drawback of potassium chloride is that if used in excess, it might  lead to the development of hard residue in your water pipes and plumping system hence blocking water passage.

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Should water leave the water conditioner during the backwash regeneration cycle?

Yes. Water is allowed to leave the water conditioner because of the following reasons:
1. To flush up the resin tank of the water conditioner
2. To re-fill the brine tank as more water is used to recharge the brine from the brine tank in the water conditioner
3. And lastly, to finish flushing up and preparing the resin tank for more water to enter.

What are the controls on a water softener and its functions?

The controls on the water conditioner are mainly set up to specify;
1. How much sodium chloride (common table salt) or potassium chloride should be used during the water conditioner regeneration cycle.
2. How often, for instance, once a week, once every two days, etc. the automatic periodic regeneration cycle should take place.
3. The time of the day the water softener should undergo regeneration- in most cases its set at 2 AM or so because at this time the need for soft water is minimal if not zero.
4. The amount of water that should be during the water conditioner’s backwash cycle. The installer usually does this by adjusting the time duration of the backwash regeneration cycle.

For most softeners, usually, this time is set at 10 minutes of backwash time by the manufacturer. The installer may adjust this cycle to a time ranging between 5 to 30 minutes as required.

This is because the number of water gallons used during the water conditioner backwash regeneration cycle varies depending on the rate of flow of water and water pressure in the house’s plumbing system.

In most cases, a typical volume of about 30 to 35 gallons of water for 10 minutes is used during the backwash cycle. However, this volume varies depending on the specific model of water softener you’re using. This figure could be even up to 150 GPM for 30 minutes, again depending on the same.

However, if you notice that your water softener is running for a period longer than 30 minutes during the backwash cycle, then something must be wrong. You should consult an expert or your water softener installer on the same.

How to use a water softener

If you are looking for water softeners for your home, it would be nice to find out how to use one. It is very easy to operate most home water softening systems even though there may be slight differences by brand and model.

Fundamentally, most types of softeners will have similar rules to follow, basic installation instructions and maintenance instructions.

Sodium is used by most water softeners to remove hard water. Individuals with high blood pressure, kidney problems or other medical conditions that limit the presence of sodium in their diet should consider using potassium rather than salt or sodium.

To begin using water softeners;
1. Refill the brine tank with the recommended amount of water. Refer to your manual for proper water level.

2. After refilling the brine tank with water, place the recommended amount of sodium or potassium into the appropriate compartment. Sodium is not as expensive as potassium. If you use potassium, make sure not to place more than one packet of potassium because too much potassium can ironically harden the water.

3. Set the time and date on which you placed the softener on the control panel. Now adjust the appropriate hardness level on the machine. You can determine your hardness, prior to installing your water softener.
You can test your water hardness with a home test kit. Adjusting the correct hardness level will allow your machine to run efficiently.

4. Adjust your water supply system so it recharges automatically. The perfect time to recharge is when everyone back home is asleep. For charging to be effective, it should work when hot water is not used in the household. Thus, towards midnight or after midnight is a good time when dishes or laundry are done and when people at home have finished taking hot baths.

5. Recharge the water softeners at regular intervals. The intervals can be manually selected. If your device has a sensor, it can be recharged automatically if needed. For manual recharge setting, you should ask the manufacturer for the ideal intervals between loads.

Types of water softeners

Nearly all softeners produce the same results, the only difference being their configuration and the kind of process initiated by them.

While more recent models use potassium chloride to soften, older models may carry out longer regeneration processes.

Generally, a water softener is classified according to its work. It can be controlled manually, semi-automatically or fully automated.

In case of a manual gadget, the operator needs to frequently open and close valves in order to control regeneration or back flushing.

Semiautomatic gadgets require users to press various buttons to start regeneration cycles, while fully automated gadgets simply require you to set the timer.

Rest operations are independently managed. Sometimes owners look for a regeneration process on request where reloading and other operations are done automatically, depending on the state of the water. These water softeners include twin-tank brine and softener tanks. While one softens, another recharges simultaneously.

Important Types:

Salt free units : This unit requires no salt substitute for softening purposes. It uses nanotechnology to get rid of ions. The atoms are initially positioned to reach a binding site and prevent calcium or magnesium ions from attaching to the water surface. In a way, the scaling of lime is controlled and all processes are carried out in an environmentally friendly way.

Ion exchange system: In this type of machine, salt alternatives are used to initiate the process. A medium is covered by potassium or sodium and is exchanged with the calcium and magnesium ions of the water. It is the most widely used of all water softeners.

Magnetic units: These machines utilize magnets and carbonate salts to soften water through the precipitation of mineral ions. However, it does not completely remove the minerals found in hard water. Nevertheless, mineral formation is reduced to a great extent.

Reverse osmosis systems: This gadget consists of a semipermeable membrane for getting rid of ions and impurities. A sufficient quantity of pressure is applied to the water to remove impurities and salts trapped in the membrane. This process is very effective, but very slow and costly.

Those were the most popular water softener systems. Depending on your individual requirements, you can buy the kind of water softener that suits you best.

How do I know my water softener is working?

3 ways to know that your water softener is working are;

1. You Feel Cleaner
Water softeners can filter your water and eliminate various contaminants. This means that these things do not end up on your skin while you are showering. That being so, you will be able to work a better lather with your soap, and you will feel cleaner after your shower is complete. The softener will allow you to feel cleaner, and it will make your showers more enjoyable.

No Soap Scum

One more advantage that water softeners provide is that they keep your bathtub and shower cleaner after it has been used. If you don’t have a water softener, it is not uncommon for a layer of soap scum to be left behind in a tub or shower after it has been used.

That’s because the contaminants in the water make it impossible to wash all the soap out of the bathtub. This leads to a layer of soap foam left behind. But with a softener in your house, you can keep your shower cleaner.

Cleaner Pipes
Water softeners can help you to keep the pipes in your home clean as well. In many instances, a home without this device will have chemicals like calcium in the water. These chemicals then run down the pipes and may leave deposits.

These deposits eventually build up, and this makes the pipes more susceptible to blockages or, in severe cases, cracks. A softener can help you keep your pipes clean, and it will be good for your pipes in the long run.
Overall, water softeners offer these benefits.


Water softening systems can help reduce the ill effects of water in your household’s plumbing and reduce sediments from clogging your pipes. These machines can lower your plumbing maintenance costs and stop you from buying or repairing appliances like coffee makers and shower heaters too often.

These softeners can improve your washing machines or dishwasher’s work and stop stiff laundry and cloudy glassware. Some people get dry skin and hair with water which may be prevented by employing a softening system in your home or bathroom. These appliances can also prevent water from staining your toilet, bathroom tiles, bathtubs, and sinks.