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Home » Water Softeners » Upflow vs Downflow Water Softener

Upflow vs Downflow Water Softener

By: Craig Smith
Last Updated:
Upflow vs Downflow Water Softener

For many years now people have been installing water softeners in their homes to combat the problems that are caused by having hard water minerals in their tap water.

Although there are many different types of water softeners available, salt-based water softening systems work the best.

The only problems are people complain about them using too much salt and producing too much wastewater.

Manufacturers then started to produce a new style of salt-based water softener where water flowed differently through the resin tank. This was called an upflow-style water softener.

Here I will compare an upflow vs downflow water softener. I will describe how each style water softener works, its advantages and disadvantages, and the situations where you would choose one style over the other.  

Main Difference Between Upflow and Downflow Water Softeners


For those who are not familiar with how water softeners work, salt-based-style water softeners consist of a brine tank that contains a salt solution and a main tank that is bottom loaded with resin beads.

Two tanks are necessary to accommodate the highly efficient ion-exchange process that takes place in the resin tank (see photo above). There is no more impactful way to remove hard water minerals from your water.

So, what’s the big difference between upflow and downflow water softeners?

As you might have guessed it’s the way that the water flows through the systems main resin tank.

In upflow-style water softeners, during the brining process, the brine solution flows from the bottom to the top. The unfiltered water that enters the system will also go into the bottom of the tank and pass up through the resin.

Quite the opposite is true with downflow water softeners. Both the incoming water and the brining flow goes from the top to the bottom of the tank.

It must also be said that as far as being effective, there is not much difference between an upflow and downflow style water softener.

It’s the little advantages that upflow water softener technology offers that make them among the best water softeners that you can by.

I will discuss some of those advantages next.

How Does an Upflow Water Softener Work?

Upflow water softeners are becoming very popular in the marketplace. Why are they now the preferred choice among the different styles of water softeners that are available? Here are some of the reasons.

For starters, because of the way the water flows through the system, they only need to recharge depleted resin during the system’s regeneration process (a cleaning process also known as backwashing).

When dirty water comes from your home’s water source and into their resin tank, it does not immediately contact the resin beads and start the water softening ion-exchange process like in traditional water softeners.

Fleck 5600SXT

Instead, it will pass down through a tube that’s placed in the center of the main resin tank.

So, the actual ion exchange process that these upflow systems use to soften water, first takes place at the bottom of the main tank on them when incoming dirty water first contacts their resin mesh setup.  

This is unlike traditional salt-based downflow water softeners which always recharge 100% of the resin in them. As a result of this more efficient brining, the regeneration process they require needs to be performed less often.

Those who use these upflow systems then get the benefit of having to use less salt to maintain performance and since regeneration is done less often there is a lower amount of wastewater produced by them.    

This also results in you having to add salt to the system less often which, in turn, makes upflow style water softeners much easier to maintain.

Part of this is also aided by this style of water softener’s ability to produce a sort of anti-gravity motion as the water passes upward through the resin. This adds to the efficiency of the water softening process.

Many of these more advanced style water softeners also come with programmable control heads. This simplifies the amount of maintenance required on your part when you own them even further.   



  • Less maintenance
  • Uses less salt
  • Advanced controls (in most cases)
  • Efficient anti-gravity flow motion
  • Cuts down on wastewater
  • Only depleted resin needs recharging
  • DIY installation compatible


  • Higher initial cost
  • Poor quality well water impacts their valve & injector operation
  • Most require an electrical connection

How Does a Downflow Water Softener Work?

When these water softening systems first became available for use, nobody thought much about how the water entering them and flowing from top to bottom would impact performance.        

Once the incoming hard water has gone down through the resin beads it then proceeds back up through a tube in the center of the resin tank and exits back out into your main water line and into your taps.


These systems biggest drawback is that they push dirty water back through the resin during the regeneration process.

This results in them being less efficient when they start to work again because they are then not as clean as possible.

Homeowners with downflow style water softeners also complain that they must add salt too often (which comes in heavy bags and adds an extra operational cost) and about the amount of wastewater produced during backwashing (regeneration).

Here is a quick overview of the pros and cons of downflow-style water softeners:


  • Simpler to operate
  • Less expensive
  • Better for poor quality well water
  • Usually require no electrical connect
  • DIY installation compatible


  • More wastewater produced than with upflow models
  • Uses salt faster than with upflow models
  • Tends to regenerate more often
  • More maintenance required

Which Water Softener is Best for Which Situation?

There are very few situations where I would not choose an upflow-style water softener over a downflow style.

That’s because if you can afford them, what upflow water softeners have to offer over older downflow water softener technology is very substantial.

I have already gone over that situation above.

But there is one inherent problem with upflow style water softeners when used to soften poor quality well water.

That’s the valves and injectors on the salt tank that allow the brine solution (salt solution) to flow into the resin tank, often becoming coated with impurities found in the well water.

This can cause the brining process to experience problems while it’s being done or shut down the system all together.

When this happens, you will need to open the brine tank and clean the valves and injectors. Trust me, this is a time-consuming project, and you would not want to do it on a regular basis.   

You may want to call a professional to do it if it happens to you, but those expenses will add up over time.

So in most situations I would recommend that you purchase an upflow type water softener unless your water source is a well and that water is of very poor quality when it comes into your home.

Is an Upflow or Downflow Water Softener Best for You?

Yes, there is much debate between whether an upflow water softener is worth paying the extra money for over a downflow style water softening system.

If you have hard water coming into your home that is causing you fits because of the extra cleaning of limescale involved and the potential for other related problems, you really can’t go wrong with either type of water softener.

Your choice will come down to which style water softener that you can best afford, how concerned you are about wasting water, and if you want to keep the maintenance of your water softener to a minimum.

If the latter two concerns are important to you and you can fit it into your budget, then I would highly recommend that you go with an upflow-style water softener.  

Photo of author
Craig Smith
Craig got his start in water working in the swimming pool and spa industry. Water treatment would grow into his main career but he ended up working in the pool industry for over 26 years where much of his time was spent balancing the water in customer's swimming pools and installing water filtration equipment. Craig offers an abundance of water treatment knowledge after helping homeowners get pure water for 26 years.

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