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Water Softeners

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SKU#: 35921 | IN STOCK

Water Softening System (3-4 Bath)

The Pentair Water Softener is our premium, whole-house, on-demand salt-based water softening system.
Effectively prevents hard water scale buildup in plumbing and appliances, helping to increase their efficiency and lifespan.
  • Enjoy softer skin, shinier hair, and softer, right-out-of-the-dryer laundry
  • Best for homes with 3-4 bathrooms
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SALE $1,860.00

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Water Softening System (3-4 Bath)
Water Softening System (3-4 Bath)
SKU#: 35921
SALE $1,302.00


Benefits of a Water Softener

Hard water levels can range from low to very high hard water. Homeowners with any level of hard water can face issues like prematurely broken water heaters and persistent scaling, spotty dishes and glassware, dingy and stiff laundry, itchy skin, and dull hair. With a Pentair Water Softener, you can reduce the havoc hard water can cause to your home and can save salt and water with our on-demand regeneration feature. When you insist on Pentair, you can expect better quality water from every tap in your home. Pentair recommends that you test your water hardness levels using our 16-Point Rapid Water Test to ensure the water softener is right for your home water. Additional features include:
  • Simple, electronic system for easier programming
  • Self-cleaning brine injector reduces maintenance
  • Only regenerates when needed, saving salt and water
  • Singular rotary disc seal means longer product life and less maintenance
  • Remote monitoring and low-salt level alert when paired with the Connected Salt Level Sensor and the Pentair Home App

Improve Appliance Efficiency


Enjoy Softer Laundry


Reduce Scale Buildup


Limit Water Spots on Glassware 

How it works



Occurs when water passes through the mineral tank where positively-charged calcium and magnesium ions are exchanged with sodium onto the negatively-charged resin beads. The calcium and magnesium are retained on the media within the resin tank while the remainder of the water with sodium ions flows into the home, resulting in softened water. Eventually, all sodium ions are exchanged with the magnesium and calcium on the resin beads fill with calcium and magnesium and need to be regenerated.


The mineral tank is recharged with sodium from the brine tank solution and displaces calcium and magnesium, which is flushed down the drain during the backwashing phase.


At the end of the regeneration process, this stage is a final removal of the hardness ions and dirt that has accumulated in the mineral tank and flushes to the drain.


The mineral tank is rinsed with fresh water and loads the brine tank so that it is ready for the next softening cycle.


Recharging cycles are controlled by the electronic meter on the top of the tank. This can be set to recharge every specified number of days or as the electronic head recognizes that a certain amount of water has been used.

Water Softeners Comparison

  Salt-Free Water Softener Alternative Carbon Water Filter & Water Softener Combo System Water Softener
Whole home solution X X X
Electronically programmable     X
Neutralizes ions, leaving in beneficial minerals
X X  
On-demand water regeneration reduces waste water
No electricity required
to operate

X X  
Multiple sizes available for any size home X X X
No salt refills necessary X X  
Indoor/Outdoor Installation X X X
Material Stainless Steel Stainless Steel Fiberglass
Reduces foul taste and odor associated with chlorine   X  
Optional Connectivity to Pentair Home App when paired with the Connected Salt Level Sensor     X
Effective on Hard to Moderately Hard Water     X
Removes mineral ions, like calcium and magnesium, from water      X
Explore Products Salt-Free Water Softener Alternative Carbon Water Filter & Water Softener Combo System This Product



Item #ImageMaximum Capacity (grains)Flow Rate (gpm)Inlet Connection TypeHome Size (number of bathrooms)Softening Technology
35920 33500 11.6 NPT, Male 1 to 2 Salt-Based
35921 48600 11.9 NPT, Male 3 to 4 Salt-Based
35922 64000 13.2 NPT, Male 4+ Salt-Based

What’s Included

  • Water Softener System
  • Brine Tank
  • Fittings
  • Owner's Manual / Installation Guide

Installation Information

Installation Recommendation: Professional

Location: If installing outdoors, this system should not be installed in direct sunlight without the presence of a weather cover accessory (sold separately). System should not be installed in an area that is exposed to freezing temperatures. See Owner’s Manual for details.

Additional Needs: Block Salt or Solar Salt

Connected Salt Level Sensor

The Simple Don’t-Forget-the-Salt Solution

Man installing pentair connected salt sensor

Ready to make last-minute salt runs a thing of the past. Check salt levels anytime, anywhere by adding a Connected Salt Level Sensor and the Pentair Home app to your setup. Only for salt-based water softener systems.

  • Simple in-app instructions get you activated right away
  • Universal brine tank clip fits most side-by-side and softener models
  • Provides intuitive alerts to your phone when your salt level is running low
  • WiFi & Bluetooth® wireless technology enabled*

Water Education Center

Soft water doesn’t have to be hard. Learn about what causes hard water and identify solutions to help reduce the related water woes.

Learn About Hard Water

We’re shining a spotlight on hard water’s relationship with laundry and how you can achieve fresher, fluffier, right-out-of-the-dryer clothes with softer water.

Learn More

Beyond taste and odor, the volatile chemical nature of chlorine means it can react and form potentially harmful byproducts. But, how much chlorine is ‘safe’?

Learn About Chlorine

Learn more about common water problems and how to tackle them in our Water Education Center.

Still Not Sure? Call us to speak with a Pentair Water Solutions home water expert.
We are here to answer your questions.

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*The Bluetooth® word mark and logos are registered trademarks owned by the Bluetooth SIG, Inc. and any use of such marks by Pentair Management Company is under license. Other trademarks and trade names are those of their respective owners.

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