Photo of a home water softener systemWater Softener Resin Replacement
How to install or replace resin in a water softener

  • WATER SOFTENER RESIN REPLACE - CONTENTS: How to replace the resin media in a water softener treatment tank. Water softener media life, contaminants, cleaning, & replacement sources: where to buy water softener resin media & other parts needed to replace the media in a water conditioner.
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Water softener resin replacement instructions: this article describes procedures replacing the resin media in a water conditioner or water softener.

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Water Softener Treatment Tank Resin Replacement Procedure

ProTec Water Softener, Surprise Arizona (C) Daniel FriedmanReader Question: how to replace the resin media inside of a water softener

8/31/14 Ron Fix It Man said:

My softener is 13 years old and I have read the resin becomes ineffective in about that life time. Iron out has been used with little benefit. Effectiveness of the softener has declined unless greater amounts of salt per cycle are used.

Troubleshooting reveals no improper cycle operation. Is it true the resin has a limited life? Can it be restored, say with a wash of dilute muriatic acid? If not, where can it be purchased?

This question appeared originally at DIAGNOSE WATER SOFTENER PROBLEMS

Reply: procedure to replace water softener treatment tank resin media


Indeed it is possible to replace the resin in a water softener.

Water softener resin can last for 20 years or even longer, but may have a shorter life depending on the chemistry of the water being processed in the water softener. Some of the sources we reviewed give the view that chlorinated municipal water can cause water softener resin beads to deteriorate while others focused on iron contamination or even algae growth that could not be flushed from the resin tank. Another common water softener resin tank contaminant is sand or debris entering the softener from sediment-containing well water.

Water softener resin that has been fouled by iron or by organic growth such as algae can often be cleaned by treating the resin tank with a resin cleaner (Iron-out, ResUp, Bleach treatments - WELL CHLORINATION & DISINFECTION ) sold by your manufacturer or by separate water softener rehab suppliers (some are listed below in this article).

See SOFTENER CLEANING & SANITIZING for advice about cleaning the water softener if you want to try this before replacing its resin.

I would contact the manufacturer of the brand of water softener you already own to obtain an installation an maintenance manual if you don't already have one. That should show how to open the tank, replace the resin media (typical cost for the resin is around $100 U.S. from third party suppliers but I'd prefer to use what the manufacturer provides).

At the same time you might find that there are controls that need repair or rebuilding such as replacing O-rings, check valves, or other controls. It makes sense to do these repairs at the same time.

Watch out: Before replacing the resin in the water softener I'd want to be sure that the unit is otherwise operating properly. A very simple check would be to inspect for SNAFUs such as those we discuss in this article series (such as improper brine tank operation, sticking brine tank float, or other causes of not-softening). If on the other hand you don't see a proper water volume entering and leaving the brine tank then the problem is probably there, not with the resin.

Then run the water softener through a regen cycle, observe that water does enter the brine tank, that salty water does backwash through the water softener and out through its drain. Confirm that your softener is using the proper salt dose by measuring incoming water hardness.

Then measure the hardness of treated water after a water softener regeneration cycle. If the unit is indeed not softening the water then media replacement may be in order. You'll need between .6 cu. ft. and about 2 cu. ft. depending on the volume or size of your water softener treatment tank.

Illustrated Guide to Installing Gravel and/or Resin into the Resin Tank of a Water Softener

Prepare the Resin Tank to Insert Gravel & Resin - using a Pentair Fleck 5800 LXT Downflow/Upflow water softener as example

Water softener resin tank before resin is added (C) Daniel Friedman Water softener resin tank before resin is added (C) Daniel Friedman

Photos above: a fiberglass (Vertex poly-glass 13x54-inch resin tank #65018 with central tub) water softener resin tank as delivered new, empty.

You can see the water softener distribution basket, a simple plastic filter screen on the bottom end of the water softener resin tank distribution riser pipe - this is the water pick-up tube that will be inserted into the resin tank. More about distribution riser pipes and how they may need replacement is found at WATER SOFTENER RESIN LOSS

This resin tank will be assembled with a Fleck water softener control valve head #V5800MEDS SPEC# 5816-01LXTB34. The control head uses an electronic timer (LXT-DC) for a "System 4 Meter" that operates on 12VDC via a voltage power adapter. The Brine valve is #1600, Injector size 1, meter size 3/4" turbine.

The second photo above shows the tube inserted into the resin tank. The open end of this tube will be connected to the softener control valve in the head of the water softener.

Water softener resin tank riser pipe open end taped to permit filling of the tank with gravel, then resin (C) Daniel Friedman

The quantity of resin required for the resin tank of a water softener depends on the tank size and is specified by the manufacturer [below].

Fleck water softener resin tank  specifications (C) Daniel Friedman

Preparation of Gravel Media for Water Resin Tank Base

But first the tank needs to be filled with a layer of filtering gravel material in the tank bottom and then with the manufacturer's specified quantity of water softener resin.

Below: first gravel is washed thoroughly before it is inserted into the bottom of the water softener resin tank. The gravel acts as a filter to prevent loss of water softener resin beads.

Washed gravel inserted into the bottom of the Fleck water softener resin tank (C) Daniel Friedman Washed gravel inserted into the bottom of the Fleck water softener resin tank (C) Daniel Friedman

The size of this smooth gravel placed into the bottom of the water softener resin tank ranges from about 5mm to 1cm. It was placed to a depth of about 1 1/2 feet, covering the distribution basket and lower portion of the distribution riser pipe.

Below: we're using a plastic bottle fit over the taped end of the resin tank riser pipe to funnel first gravel, then resin, into the softener tank.

Placing gravel then resin into the water softener resin tank (C) Daniel Friedman

Properties of Water Softener Resin

Below: our softener required three cubic feet of Purolite water softener resin beads.

Purolite Water Sofener REsin, 1 cubic foot bag (C) Daniel Friedman

Below for the scientifically-curious reader we show close-up photographs of Purolite® water softener resin beads. You can see that the resin particles vary in size but are about 0.4 to 1mm in diameter.

Purloite water softener resin beads under the microscope (C) Daniel Friedman Purloite water softener resin beads under the microscope (C) Daniel Friedman

Watch out: Spilling these water softener resin beads on a walking surface will make it about as slippery as wet algae, with a very low static coefficient of friction (SCOF). What that means for normal people is if you step in this stuff you will fall on your you-know-what.

As we were working on a high (flat) rooftop in San Miguel de Allende, and as I didn't want to have to visit the mothers of the other workers to explain why they fell off of the rooftop, we took great care to sweep up any spillage immediately and very thoroughly.

More about the SCOF and about these resin beads is also at SLIPPERY STAIRS, WALKS

Commonsense Precautions to Observe when Handling Water Softener Resin

Here is the Purolite® MSDS for Water Softener Resin Beads, [PDF] used for ion exchange, adsorbent, and/or Catalyst, Purolite® C100, Purolite 150 Monument Road Bala Cynwyd, PA 19004 USA Tel:+1 610 668 9090, Manufacturer: Purolite S.R.L. Str.Aleea Uzinei nr.11, 505700 Victoria, Judetul Brasov, Romania, and Purolite (China) Co. Limited Qianlong Economic Development Zone, Qianyuan Town, Deqing County, Huzhou City, Zhejiang, China 313216.

The MSDS for these water softener resin beads indicates that "The mixture does not meet the criteria for classification." and also suggests Observe good industrial hygiene practices. Use personal protective equipment as required. and also Wash hands after handling. Get medical advice/attention if you feel unwell.

Inhalation - Move into fresh air and keep at rest. Get medical attention if any discomfort continues.

Skin contact - Wash off immediately with soap and plenty of water. If irritation persists get medical attention.

Eye contact - -Immediately flush with plenty of water for at least 15 minutes. If easy to do, remove contact lenses. If eye irritation persists, get medical advice/attention.

Ingestion - Rinse mouth thoroughly. Never give liquid to an unconscious person. Do not induce vomiting. If vomiting occurs, the head should be kept low so that stomach vomit doesn't enter the lungs. Get medical attention if any discomfort continues.

Most important symptoms and effects, both acute and delayed - Eye contact: Contact may cause irritation with redness, tearing, pain, and/or blurred vision.

General information - If you feel unwell, seek medical advice (show the label where possible). Ensure that medical personnel are aware of the material(s) involved, and take precautions to protect themselves.

Install the Water Softener Control Head When Resin Tank is Filled

Below: an under-side view of the Fleck water softener control valve head.

Fleck water softener control valve head under-side view (C) Daniel Friedman

When the resin tank has had its gravel and resin installed, the control head is re-connected to the tank.

Watch out: when replacing the softener control head by re-connecting it to the water softener body, Fleck warns [with minor edits for clarity]

DO NOT exceed 15 ft-lbs (foot pounds) of torque when installing the water softener control head to the resin tank body.

Exceeding this torque limit may damage the threads and cause water softener failure (and leaks).

Spin the valve onto the tank making sure that the threads are not cross-threaded, then rotate the valve freely without using force until it comes to a stop. (This position is considered "zero").

Then rotate the valve clockwise from "zero" to between 1/4 turn and 1/2 turn. STOP THERE.

At WATER SOFTENER RESIN LOSS we give additional details about the procedure for assembling the control head to the resin tank body.

Adjust the Water Softener Controls After Refilling Resin Tank

Below: the Fleck or Pentair water softener control head has been installed and is connected to the building water supply piping. The bypass valve on the water softener is set to SERVICE. As this is a new water softener installation (with new resin in the resin tank), the installer will need to set the water softener program or controls.


Water softener control head installed and ready for programming on a new Pentair Water Softener (Fleck) (C) Daniel Friedman

Watch out: At a new water softener installation or after sanitizing a water softener brine tank, you may need to run a regeneration cycle with an empty brine tank to be sure that you've flushed out debris in the system. Failure to adequately wash gravel installed in the base of a water softener resin tank or failure to flush out debris that is generated normally by plumbing work on a building can cause downstream sediment or charcoal filters to clog up very rapidly.


Before the first water softener regen cycle the softener must be programmed with proper salt dose and regeneration frequency. The specific parameters that must be set on a water softener control or timer will vary significantly among water softener models. Simple models simply set a salt dose and regen frequency while more sophisticated water softener controllers will want to be told the hardness of the water softener and the size or capacity of the resin tank.

Place Salt into the Water Softener Brine Tank

Below: A view into the empty salt or brine tank of the new water softener. You can see the covered-over brine tank float tube in the left side of the picture and the white salt screen at the bottom of the brine tank. The salt screen permits any soil mixed in with your salt to settle below the screen.

Empty water softener brine tank (C) Daniel Friedman Water softener brine salt tank with initial salt installed (C) Daniel Friedman

Our second photo (above) shows our initial installation of salt pellets into the brine tank. One 80 lb bag of salt (32.6 kilos) was enough to put the water softener into operation; later we filled the salt tank to near its top with salt pellets.

Tru-Soft water softener pellets (C) Daniel Friedman

Also see SALT DOSE SETTING, WATER SOFTENER and if you're having trouble with the brine tank see

Below: the Pentair Water Systems - Fleck water softener control valve head display showing the remaining water capacity before the unit will need to run a regeneration cycle.

The softening capacity in liters (or gallons) depends on the supply water hardness, the resin tank size, and the volume of water usage. Our water softener was labeled Pentair, from Water Quality Systems, 5730 North Glen Park Road, Milwaukee WI 53209 USA, Tel: 262-238-4400,

Fleck water softener control valve head showing remaining capacity (C) Daniel Friedman

However the control head and manual label the equipment as by Fleck water softeners, adding to the usual confusion about identifying water softener brands and finding their manuals. WATER CONDITIONER / SOFTENER MANUALS provides free manuals and contact information for nearly all water softener or water conditioner brands.

Run First Softener Regeneration Cycle

Once the water softener is programmed, the brine tank full and you've checked to confirm that it is in SERVICE mode (see FLECK or PENTAIR WATER SOFTENER BYPASS VALVE) and that there are no plumbing leaks, run a first cycle or manual regeneration cycle.

Summary of 13 Steps To Replace the Water Softener Tank Resin

Autotrol 400 control sketch

  1. Put the building water supply on bypass to assure that water will remain available while the water softener is offline.

    Watch out: I would not begin the disassembly of a water softener tank for resin replacement without first being sure I could leave the building with a working water supply - by installing bypass controls on water piping at the softener location if necessary

    Watch out: I would also want to have on hand any replacement parts I'm likely to need such as the softener tank bottom water distributor and riser tube, O-rings, gaskets and seals. Having those parts ready not only speeds the softener resin replacement job itself, avoiding delays waiting for parts, it also reduces the risk that you think the job is done only to find that your re-charged water softener is leaking now that it has been re-assembled.

  2. Disconnect the water softener from any electrical power supply
  3. Remove the controls and softener head: the control valve or head needs to be removed from the water softener treatment tank.
  4. Flush out / vacuum out the old water softener resin. Smaller water softener tanks may be tipped over and flushed out, or you may need to use a wet-dry shop vac to remove the resin from the tank.

    Watch out: Check the level of resin in the water softener tank before you remove the old resin. You'll probably see that it fills the softener tank to about 1/3 from the tank top - a detail you'll use in calculating the amount of replacement water softener resin required.

    Notice that some water softeners may include a sanitary gravel bed on the tank bottom that also needs to be cleaned or replaced.
  5. Clean and disinfect the softener's water treatment tank. See our bleach dilution and disinfection advice at DISINFECTING BUILDINGS with BLEACH or for more detail and more extensive disinfection methods, at WELL CHLORINATION & DISINFECTION
  6. Replace the water softener internal water distributor and riser tube (that's why I said to first check with your softener manufacturer for parts supply and to have these on hand)
  7. Pour the new resin into the softener treatment tank up to the same level that you found resin before emptying the tank, or as your manufacturer directs for your softener model and size. You can measure the tank size to estimate the necessary volume.

    Vcyl = pi x r2 x h

    where pi = 3.1416,
    r = the radius of the circle formed by the cylinder (inside of the softener treatment tank), and is simply 1/2 of the tank's inside diameter
    h = the height of the cylinder of space inside the softener

    Watch out! be sure to write the radius and height in the same units of measure - we use inches.

    Note: the water softener resin tank is not filled with resin right to the top of the tank. Entering water needs space to mix with and interact (exchange ions with) the resin beads. Taller water softener tanks (over 40") are filled to about 60% while shorter water softener tanks may be filled to about 80% of their internal volume capacity.

  8. Reassemble the water conditioner treatment tank, including the new O-rings and seals that fit your tank as we suggested earlier.
  9. Run the water softener through an extra regeneration cycle
  10. Test and compare the water hardness levels before and after the water has passed through the water softener.
  11. Check / set the water conditioner control settings: check that you have set the proper regeneration cycle frequency and salt dose for the hardness of your water and the typical daily water volume used. See SOFTENER ADJUSTMENT & CONTROLS
  12. Restore the water softener to operation
  13. Check for leaks

Sources of water softener tank resin to replace original material

Water softener installation in San Miguel de Allende (C) Daniel FriedmanBelow: the Fleck water softener installed in San Miguel de Allende. Also see WATER QUALITY & QUANTITY San Miguel de Allende.

Typical water softener resin is sold in bead-form, as a conventional gel polystyrene sulfonate cation exchange resin that is ready for use in household or industrial water conditioning equipment such as a water softener or water conditioner. The resin should meet the specifications of your water softener manufacturer, and/or the U. S. Food and Drugs Code of the Federal Regulations section 21 paragraph 173.25.

Diagnose & Fix Water Softener Problems: this article series describes procedures for diagnosing and repairing water softener or water conditioner problems including water conditioner control settings and adjustment or repair, brine tank and brine tank float cleaning and repair, and the proper amount of water softening or conditioning that is needed.

Reader Question: life of Culligan Mark 10 water softener resin

(Feb 17, 2013) Eric said:

I have a Culligan Mark 10 system and the Culligan folks came out to inspect what I think is a failing valve. Sure enough they concluded that the valve is failing, but they did their typical sales thing and offered to: replace the valve with modern technology and keep the resin tank in place, re-resin the tank, and flush the brine tank.

What is the life of resin? The Culligan guy said "15-20 years maximum". The system has now been unplugged for 3 weeks while we consider these options - does it take much to just start this back up if I go buy my own valve and install it?



If your water softener has been out of service for some time or is old, it would be appropriate to sanitize the unit - see SOFTENER CLEANING & SANITIZING for that procedure.

The life of water softener resins is indeed limited and I agree with your Cullligan representative. But you might want to take a look at



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