What Is the Best Water Softener for Septic Systems

Can I use a water softener with a septic system?

Only the best water softener for septic systems is recommended. Research that has been conducted by different foundations, associations, and universities suggests that only the most efficient water softeners should be used with a septic system. The ideal amount of sodium in the wastewater can improve the biological performance of a septic system.

But the thing is, the market is packed with different kinds of water softeners that claim to be high-performing and efficient. We conducted detailed research and came up with nine models that regenerate most efficiently and are most septic-friendly.

Top Pick

Abundant Flow Water WS-48K-91SXT Water Softener is our top pick. This new release features the most advanced twin valve system that alternates between two tanks to ensure that you never run out of soft water. The system regenerates only when needed, making it septic-friendly.

Best Water Softeners for Septic Systems

1. Abundant Flow Water WS-48K-91SXT Water Softener — Best Overall

Efficient regeneration is key to choosing a septic-friendly solution. If you are searching for the most efficient water softener that regenerates only when necessary, the WS-48K-91SXT from Abundant Flow Water fits the description.

The most impressive feature that comes with this model is the Fleck 9100SXT twin control valve, which delivers a constant flow rate of 12 gallons per minute. The digital meter that works with the valve reads water usage electronically even during a power loss. It regenerates when necessary, which means it doesn’t drain excess water containing salt into your septic system.

The system has dual alternating tanks and each tank has a 48,000-grain capacity. The system switches to the second tank while the other one regenerates.

Key Features

  • Fleck 9100SXT valve
  • Digital meter
  • Dual alternating tanks
  • Polyglass tank
  • High-capacity resin


  • Dual tank system ensures continuous regeneration
  • The high flow rate treats high levels of hardness
  • Regenerates when necessary, making it salt-efficient and septic-friendly
  • The innovative second tank allows for quick connection
  • The fiber-reinforced polymer valve is corrosion-resistant


  • The system is not space-saving
  • It is quite an expensive choice for anyone working with a tight budget


The dual-tank design and ability to immediately regenerate when needed make the Abundant Flow Water WS-48K-91SXT the best overall choice for septic systems.

2. AFWFilters Fleck 64,000 Grains Water Softener — Best Bypass Design

This is an on-demand digital metered water softener with a high capacity of 64,000 grains. The system is very effective at removing hard minerals and iron from your water. It is also septic system friendly.

The high-performance metered design of this model measures your water usage and regenerates only when needed. This ensures that less salt is introduced into your septic system in the long run. The digital control panel allows you to make simple adjustments to minimize salt usage and maximize capacity.

We appreciate the bypass valve design that allows you to bypass the system without the need to shut off your main water supply. You’ve also got a safety float in the brine tank that prevents accidental overfilling.

Key Features

  • 64,000-grain capacity
  • Digital metered control
  • 8 percent crosslink resin
  • Bypass valve
  • Standard brine tank
  • Safety float


  • It measures the water that you use in your household
  • Regenerates when needed to avoid exhausting the septic system
  • The digital control panel is easy to program
  • You can bypass the system without shutting off the main water supply
  • It can effectively remove up to 20 GPG of hardness


  • The 8 percent resin isn’t as long-lasting as the 10 percent resin
  • The installation process is not entirely easy


This is a great model for those draining into their septic systems. It only regenerates when necessary and has a safety float for preventing overfilling.

3. Aquasure AS-SE1500A Water Softener — Most Versatile System

What if your household needs a more versatile system? For a whole-house, septic-friendly water softening solution for a household of up to seven people, the AS-SE1500A from Aquasure should be the answer.

Apart from removing minerals causing hardness in your water, the complete system is also designed to remove chlorine, contaminants, and heavy metals. Because of this, the wastewater will not be damaging to your septic system. The water softener comes equipped with a digital metered control valve, which lets it regenerate only when needed. This ensures your septic tank doesn’t overflow with brine discharge.

The system usually comes with installation instructions, and you can even find installation videos online. But it is possible to receive a model with some missing accessories.

Key Features

  • 64,000-grain capacity
  • Digital metered control valve
  • Cradle base
  • High-capacity resin
  • Heavy-duty brine tank
  • Safety float feature


  • Installing the system is a breeze with the provided instructions
  • Regenerates only when needed to avoid overflowing the septic tank
  • The digital metered control valve monitors water usage
  • The high-capacity resin will last a long while
  • The safety float makes sure the brine tank doesn’t overflow


  • The power cable for the softener head unit isn’t long enough
  • The metal clamps holding the valve may end up leaking in the long run


The AS-SE1500A from Aquasure is one of the best systems that will not overflow your septic tank or cause any destruction.

4. Pentair WS48-56SXT10 Fleck Water Softener — Best Pre Filled Resin

The WS48-56SXT10 from Pentair is uniquely and innovatively made to remove hard minerals like magnesium and calcium from your water.

What makes this product qualify as one of the best models for septic systems is its metered-based regeneration. Unlike conventional systems, this water softener monitors and measures your water usage to regenerate only when necessary. This means less brine discharge is sent to your septic system, preventing overflowing and excessive salt damage.

We like the 10 percent crosslink resin that comes prefilled, considering that it is longer-lasting compared to the 8 percent resin of the competition.

Key Features

  • 48,000-grain capacity
  • 14 GPM flow rate
  • 3.5 gallons per minute water consumption
  • 10 percent crosslink resin
  • Metered based regeneration
  • Easy-to-use digital panel


  • Equipped with a digital meter for smart regeneration
  • High-capacity resin removes hard minerals like magnesium and calcium
  • Features touchpad controls for easy programming
  • High flow rate for effective removal of hard minerals
  • The safety float feature ensures your brine tank doesn’t overflow


  • It is possible to receive a mineral tank that leaks
  • Some of the installation accessories may be of the wrong size


This is a great water softener for the money that will deliver reliable metered-based regeneration to ensure that your septic system is not overrun with brine discharge.

5. DuraWater 9100SXT Fleck Water Softener — Best Twin Tank Design.

If you are looking for a water softener that comes with the simplest mechanical design and premium-quality features for your septic system, then this model from DuraWater is what you should be looking for.

The advanced 9100SXT twin valve design is the best selling feature of this water softener. It allows the system to use the full capacity of the individual tanks before regeneration takes place. This ensures there is less wastewater, making it septic-friendly.

Unlike conventional valves, the 9100SXT only requires programming once when setting up the system. In the event of a power loss, the internal capacitor in the system will keep your settings for up to forty-eight hours. It also comes equipped with a non-volatile memory standard that will ensure the settings of the system are not lost.

Key Features

  • 40,000-grain capacity
  • Fleck 9100SXT valve
  • Meter initiated regeneration
  • 2.4 GPM backwash rate
  • 12 GPM service flow rate
  • Eighty-nine gallons per regeneration
  • 18.75 pounds of salt per regeneration


  • Twin tank design ensures fewer regeneration cycles
  • It is very effective in saving salt and water
  • The 10 percent crosslink resin is highly durable
  • Safety overflow assembly ensures there is no overfilling
  • High service flow rate improves water softening


  • This system may not be the best for removing iron from the water
  • DIY installation may be a challenging task


This is a great water softener for the money that will not only reduce hardness in your water but will also go easy on your septic system.

6. Iron Pro 2 Combination Water Softener — Best for Well Water

Are you using well water in your home? The Iron Pro 2 from AFWFilters is your best bet. This system is tested to be highly efficient and septic-friendly.

The fact that it has a low capacity doesn’t interfere with its quality. The system still has a high filtering performance of up to 64,000 grains. Not to mention that regeneration only takes place when demand increases, making it a good choice for the septic system.

Although the Iron Pro 2 is recommended for a household with fewer people, its fast flow rate can effectively handle three showers, a dishwasher, two sinks, and a laundry machine running at the same time without regenerating more frequently.

As an added advantage, the system comes with a USB drive that has all the installation instructions as well as programming controls.

Key Features

  • 64,000-grain capacity
  • Digital meter control valve
  • Up to 75 GPG hardness
  • 6 to 8 ppm iron removal
  • Easy-to-use touchpad
  • Bypass and one-inch connection


  • Only regenerates when needed to avoid overflowing the septic system
  • The bypass valve allows you to bypass the system without shutting off the water
  • The fine mesh resin removes both hard minerals and iron
  • Takes a relatively short time to see reduced scale buildup in your plumbing
  • There is a safety float in the brine tank for preventing overfilling


  • Installing the system may not be an easy task for everyone
  • It may not be the best choice for a larger household


The Iron Pro 2 is a great solution for people who use well water and a septic system connected to the water softener.

7. GE Appliances GXSH40V Water Softener — Best Single Tank Design

Have you been looking for a heavy-duty and high-performing single tank water softener that is septic-friendly? Check out the GXSH40V from GE Appliances.

The SmartSoft technology featured in this water softener monitors your water usage and learns how to anticipate your demands. This way you will never have to run out of supply of softened water. The system will only regenerate when it has to. So you don’t have to worry about it overflowing your septic tank with brine discharge.

Some of the handy features of this great system include the programmable digital control panel and indicator light. It has a permanent memory, which provides reliability during power outages.

Key Features

  • 40,000-grain capacity
  • SmartSoft technology
  • 125 GPG maximum hardness
  • 8 parts per million iron removal
  • 230-pound salt capacity
  • 1.25-inch connections


  • The SmartSoft technology monitors your usage to regenerate when necessary
  • Fewer regeneration cycles will prevent your septic system from overflowing
  • A suitable system for removing high levels of hardness
  • Removes iron, preventing it from going to your septic tank
  • The electronic controls are super easy to use
  • 35% less salt consumption


  • Some parts may arrive broken out of the box
  • It is possible to come across a model with quality control issues


As long as you receive a model that doesn’t have broken parts or poor quality control, the GXSH40V from GE Appliances is a great choice for the money.

8. Tier1 WS-165-150 Water Softener — Best Demand-Initiated System

The WS-165-150 from Tier1 is uniquely designed to remove magnesium, calcium, and traces of iron from your hard water.

The innovative design of this system is septic-friendly. The high-performance digital metered control valve will only regenerate when needed. This means you have a reduced number of regeneration cycles and your septic system is unlikely to overflow or suffer any serious damage from excess brine discharge.

The digital panel is easy to program, and you can find the step-by-step guidelines in your instructions manual. This unit is demand-initiated, which means the control valve is fitted with a water use probe for improved performance.

Installing the softener is a breeze, thanks to its quick connections. You’ve also got a manual index for cycling the position, which makes installation easier and faster.

Key Features

  • 48,000-grain capacity
  • 11.2 GPM flow rate
  • Digital meter control valve
  • Demand initiated system
  • User-friendly display
  • Quick connections


  • Demand initiated system regenerates only when needed
  • The digital panel is easy to program with the ergonomic touchpad
  • Manual index and quick connections allow for easy installation
  • Removes hard minerals and scale buildup in your plumbing
  • Does a great job of extending the life of your appliances
  • Can use potassium chloride in place of salt


  • The control valve is not protected from particulates in the water


Tier1 WS-165-150 is a system that you should consider if you are to connect your softener to your septic system. It will introduce brine discharge less frequently.

9. AFWFilters WS-96K-91SXT Water Softener — Highest Flow Rates

The WS-96K-91SXT from AFWFilters is innovatively designed to remove hard minerals and any associated scale buildup in your plumbing fixtures.

What makes this model a great choice for your septic system is the digital alternating metered control head. It allows for a two-tank operation, which means you will have fewer regeneration cycles. So, it is unlikely that your septic system will overflow with brine discharge. It is one of the best twin-tank systems for homes running water with high hardness rates.

You’ve got a one-inch MNPT thread that allows for easy and quick connection to your plumbing pipes. The bypass valve, on the other hand, allows you to bypass the system without shutting off your main water supply.

Key Features

  • 96,000-grain capacity
  • Alternating digital metered control
  • Large almond brine tank
  • 8 percent crosslink resin
  • Safety float feature
  • Bypass valve
  • One-inch male connection


  • The dual-tank design regenerates less frequently
  • Suitable for treating high hardness, thanks to the high flow rates
  • The system saves a lot on water usage and salt
  • Easy to bypass the system with the bypass valve
  • Reduced wastewater makes this system highly septic-friendly


  • Some models may come with missing installation accessories
  • Could be better if it comes with a 10 percent resin


The WS-96K-91SXT from AFWFilters is engineered to deliver high-quality softened water without causing any destruction to your septic system.

Things to Consider When Looking for Water Softeners for Septic Systems

The relationship between a septic system and a water softener has been a topic of contention for many years. One thing is certain, the best water softener for septic systems has to be a high-quality, efficient model.

Here are key factors that will come in handy during your search.

Timer-Controlled Vs Metered Water Softeners

There are at least two popular methods for controlling a water softener: metered and timer controlled.

A timer-controlled system is engineered to regenerate after a preset period has elapsed, which can range from one to 12 days. It is a good design for a septic system because it only drains brine discharge at a specific period. But it is not the most efficient choice because it may regenerate before the resin is completely exhausted.

A metered or demand-initiated system is the real deal when looking for the best water softener for septic systems. This type of system features a meter control valve with a digital control panel. You can use the touchpad on the digital panel to choose your desired water softening settings. A demand-initiated system monitors and measures your water usage to regenerate only when needed. This is not only water and salt efficient, but also reduces the number of times the wastewater is discharged into your septic system.

Sizing a Water Softener

You need to choose a water softener of the right size. This way, you can effectively reduce the number of times the system has to regenerate to meet your water supply demands.

How do you size a water softener? We calculate that based on the amount of hardness that you have in your water. You will also have to consider the level of iron or manganese if you are using well water. The daily water demand is determined by adding the total compensated hardness value and daily water use.

In a household of four people, each person uses about 75 gallons per day. So the total number of gallons per day will be 4*75, which is 300 gallons. If the hardness level of the water is 10 GPG and you are using city water, then the daily water demand will be 300*10, which is 3000 grains. In a week, this household will need 21,000 grains of hardness to be removed by the softener.

What you need to do next is consult a sizing chart to find a system that will keep up with this demand without exhausting the septic system with excess wastewater. For this example, a water softener with a rating of 32,000 to 40,000 grains will be a good choice for a septic system.


Can a Water Softener Overflow a Septic Tank?

Your septic tank may overflow if your water softener regenerates more frequently and discharges a great deal of wastewater.

Should I Use a Timer-Controlled or Metered Water Softener with My Septic System?

Both systems effectively control how frequently the water softener has to regenerate. But a timer-controlled system may prove to be wasteful because it may regenerate before the resin is completely exhausted.

Should I Choose a Single Tank or Twin Tank System?

A twin-tank system is a more efficient choice for a septic system because it regenerates less frequently. When you choose to settle for a single tank system, then make sure it features a digital meter control valve.

Final Thoughts

For this roundup, the winner is Abundant Flow Water WS-48K-91SXT Water Softener. What makes this system stand out is the twin-tank design that ensures you never run out of soft water. It achieves this by using one tank to full capacity and then switching to the next tank, giving the first tank time to regenerate.

It is a demand-initiated system with a smart digital meter control valve that regenerates only when needed. This makes this model the most efficient system for cutting down on water usage and saving salt. Fewer regeneration cycles make the water softener highly friendly for septic systems.