Water purification blog

How do water softeners work – 5 regeneration phases to solve limescale problems right now

Intro to water softening systems and how do water sofeners work

How do water softeners work is an important question before you decide to install one in your home and protect your water heaters, boilers, faucets, bathtubs, washing machine, reverse osmosis system, and all other home appliances connected to a hard water supply.

Keep reading, and you will learn how do water softeners work, about all the phases and cycles a water softener system has, and how to protect a water softener with a whole house sediment filter.

As you already know, water softening systems can make a big change in the quality of life by eliminating limescale problems, including lower heating costs, lower detergents and washing powder costs, no more dry skin and hair, etc…

The advantages are numerous…

Water softener types

Water softeners can be found as simple and dual tank types. All softeners are equipped with automatic control valves such as Autotrol, Clack, Fleck, etc…

The controllers on automatic valves serve to ensure fully automatic operation and regeneration of the softener. They can be time or flow programmable.

A time programmable controller will initiate a regeneration at a programmed time regardless of the remaining capacity.

A volume programmable controller monitors the amount of softened water through a built-in flow meter in the control valve and performs a regeneration when the capacity is exhausted.

On the display of the controller, the current water flow through the softener, the remaining working capacity until regeneration, as well as the current phase of regeneration, if it is in progress, can be seen at any moment.

To connect and operate the softener, inlet (hard water) connection, a connection drain, outlet (softened water) connection and a single-phase socket for powering the softener controller are necessary.


whole house water softener

Whole House Water Softener with Pre/Post Filters

Automatic whole house water softener

  • 20” sediment cartridge that removes sediment, silt, sand, and dirt
  • Ion exchange water softener, 48,000-grain capacity, service flow: 9-11 GPM
  • 20” solid carbon cartridge for removing volatile organic carbon compounds (VOCs), insecticides, pesticides and industrial solvents

Crystal Quest has been in the water filtration industry for over 30 years. The company manufactures water filtration and softeners products to a worldwide market for residential, industrial, or commercial use.

The company makes reverse osmosis solutions, water conditioning, water treatment, industrial water filters that can be used in beauty salons, apartments, clubs, government complexes, etc.


How do water softeners work – service cycle

When a water softener gives softened water at its outlet, it is in service cycle. This is the normal cycle when the water softener system gives water without hardness on its outlet.

The hard water flows through the automatic valve of the water softener on top of the vessel, it goes through the bed of ion exchange resin. Here, in contact with tiny resin beads, the process of changing Calcium and Magnesium for Sodium is happening. Now, on the water softener’s exit you have softened water.

To learn more about the regeneration process read our post about How to remove water hardness with salt based water softener systems.

How water softener works
Dual tank water softener examples with Autotrol and Clack automatic valves

What is used to regenrate a water softener?

Salt based water softeners use salt tablets for the regeneration. In fact, salt tablets are used to make saturated brine solution, which is drawn into the softener. The salt is in contact with water in the brine tank (salt tank). Here a saturated brine solution is created, that is later used to regenerate the softeners ion exchange resin.

Instead of salt tablets, potassium chloride can also be used for regeneration.

How do water softeners work – regeneration cycles

Here are the most common regeneration cycles of salt based water softeners. Their order or number of phases may be different, but these are the most usual ones.

Backwash phase

In this phase, the ion exchange resin is flushed counter currently, so the water enters the column at its bottom, passes through the resin from the bottom upwards and is discharged into the sewer from the top of the column.

The goal of this phase is to wash out of from the resin any mechanical impurities that may have arrived with the feed water, to wash out the crushed particles of the resin, as well as to relax the resin from the effect of pressure during the service cycle.

Brine draw phase

In this phase, a saturated solution of sodium chloride (brine) is passed through the ion exchange resin, during which the resin is regenerated and converted back into its active form, ready for a new service cycle. The brine is sucked into the valve by an injector that creates a vacuum. With a slow water flow, now the brine flows also through the resin bed.

When all the brine is sucked out of the brine tank, only water flows through the resin bed. With this slow water flow, the brine is slowly washed out from the resin.

Slow rinse phase

In this phase, the excess salt is washed out from the ion exchange resin with a small flow.

Fast rinse phase

In this phase, the rinsing of the ion exchange resin is continued, but at a higher flow. The water flows through the water softener just like in the service cycle, but it is still passed to the drain.

Brine refill phase

In this phase, the brine tank is refilled with water, in order to form a salt solution for the next regeneration. During brine refill cycle the water softener already gives soft water at its outlet.

When do salt based water softener systems need to regenerate?

Each water softener has its operating capacity. It is determined by the ion exchange resin quantity and the inlet water hardness.

When the operating capacity is fully used the automatic controller will start a regeneration cycle.

After the regeneration cycle the water softener has its operating capacity restored.

Outlet water during water softener regeneration

During regeneration, with single tank water softener, hard water is bypassed so there is no water supply interruption.

Hard water is bypassed only during regeneration, which lasts about 90 minutes and this won’t make any problems for your water heater or other appliances. The regeneration is programed to start at the time when the water usage is minimal or it can be started at any time by the user.

During regeneration, with dual tank water softener, there is always soft water on the outlet, without any interruption.

How to protect your water softener?

Most important part of a water softener is the control valve. A sediment filter will protect it from damage and provide a long and trouble free lifetime.

Whole house sediment filters are easy to install and they always a recommended per filtration.


whole house sediment filter

Whole House Two Stage Water Filtration System with Sediment Filtration and Activated Carbon

The Home Master Filter Pressure Performance Series uses oversized filters, housings, and fittings to ensure a good water pressure.

Multi-gradient depth polypropylene sediment filter and a radial flow granular activated carbon filter will protect your water supply from unexpected quality changes.


How do water softeners work – possible regeneration problems

Here are some of the possible problems your water might have:

Water softeners can remove smaller contents of iron from water. However, if iron content is high it can damage the ion exchange resin and the performance of water softening. In this case you might need to remove iron before the softener.

If the inlet water pressure is low, the injector can not make a vacuum, and it can’t suck the brine into the softener. This can also happen if you have a water filter installed ahead of the softener, and the cartridge is clogged.

Sometimes, if the salt is not pressed under sufficient pressure, salt tablets in the brine tank can turn into powder. In this case there is not enough brine or the brine is not sucked into the softener.

What happens with water softeners in the case of A power outage?

In the case when the water softener gets without electrical power, it stays in the cycle it was at the moment of power interruption. When the power gets back.

In case it was in the SERVICE cycle, the only thing that happens is that the water consumption is not recorder during the outage.

In case it was regenerating, it will stay in the regeneration cycle it was when the power went out. On power restore it continues the regeneration process.



Wate purification blog

Who am I?

I am working as a water treatment technical manager and I have more than 25 years of practical experience in water purification.

After many years of experience in water treatment and purification, I want to share some of my knowledge and get people to know the real importance of water quality.

Water quality and water treatment are very complex themes, so it is important to explain them on an easy-to-read level.

On this blog, you will find many understandable, easy-to-read information about water purification.

I hope you enjoy it and thank You for reading.


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