Replacing an old water softener: what decides it.

The resin bed.

The resin is the part that does the softening, and it does wear. Purolite, a resin manufacturer, says a premium softening resin can give reliable operation for over ten years in a well designed system. It also gives a rule of thumb for what shortens that: for each 1 mg/L of chlorine in the incoming water, resin life is reduced by half, and each further 1 mg/L halves it again. Iron in the water speeds the damage up.

ResinTech, another resin manufacturer, says that whenever chlorine is above 0.5 parts per million, steps should be taken to protect the resin, either a carbon prefilter ahead of the softener or a more heavily crosslinked resin, which it says can sometimes double resin life.

Across most of our service area the disinfectant is chloramine rather than free chlorine, and both manufacturers’ figures are given for chlorine.

How the valve decides when to regenerate.

Some softeners regenerate on a timer. The Minnesota Pollution Control Agency describes timer models as running at set intervals regardless of whether the resin needs it, and recommends replacing them with demand based units. It reports that in Marshall, Minnesota, residents who replaced or optimized their water softeners reduced the amount of salt they used every year by 86 percent.

The Water Quality Association’s best practice guidance says to avoid time clocks for starting regeneration and to use demand initiated regeneration instead, and EPA’s WaterSense guide gives buyers the same direction: a model with demand initiated regeneration, lower water use and higher salt efficiency.

What NSF/ANSI 44 certifies.

NSF/ANSI 44 is the standard for residential water softeners, the kind that use a cation exchange resin regenerated with sodium or potassium chloride. EPA’s WaterSense guide notes that it includes a voluntary efficiency rating of 5.0 gallons of water or less per 1,000 grains of hardness removed: the water a softener uses for the hardness it takes out.

Texas homes on a septic system.

If the unit drains to a septic system, Texas has a rule of its own. A softener discharging to an on site sewage system must conserve water by design, regenerate using a demand initiated regeneration device, and be clearly labeled as having one.

A unit installed before September 1, 2003 can stay in use without that device, but when it is replaced, the replacement has to meet the rule.

Whether it still fits the house.

A softener is sized to the hardness of the water and to how much water the household goes through. The Minnesota Department of Health advises making sure a softener is set to the hardness of your water supply. The Water Quality Association warns against oversizing equipment and overtreating water as wasteful practices.

More people in the house, a move, or a change of supply all move those numbers. Our water softener sizing guide shows the method, and each city’s hardness is on our DFW water quality pages. What moves the price of a new unit is in our water softener cost guide.

Across the fourteen cities we serve, figures range from about 5 grains per gallon in Mansfield to about 11.8 in the NTMWD supplied cities, so a unit sized in one city may not suit the next.

What happens when the softener is replaced.

The new unit goes in on the main line, which in most homes is on the garage wall, with the drain run and a bypass valve fitted, and it is installed in one visit. One day in most homes, start to finish, and we schedule it for a day that suits you.

The new softener is sized to your water and your household, with its brine tank beside it. Together they take up about the space of a water heater. We show you what is now in the house, what it is doing and the two or three things worth knowing about living with it.

Everything is configured for your water and run on site. Nothing is left on factory settings. It carries a lifetime manufacturer warranty for as long as it is yours, and labor carries a one year warranty from the day it goes in. After the first year, a service visit is $80.

Sources

• Purolite (Ecolab), “Factors That Effect Softening Resin Performance and Life”
• ResinTech, Technical Data Sheet “Chlorine Oxidation” (REV 0421)
• Minnesota Pollution Control Agency, “Eco Living: Use less salt in your water softener to cut pollution and save money” (November 22, 2024)
• Minnesota Department of Health, “Home Water Softening Frequently Asked Questions” (last updated October 3, 2022)
• Water Quality Association, “Getting Smart with Softeners: Best Practices for Industry Professionals and Tips for Consumers”
• US EPA WaterSense, “WaterSense Guide to Selecting Water Treatment Systems” (832-F-24-024, November 2024)
• NSF International, “NSF Standards for Water Treatment Systems” (NSF/ANSI 44)
• Texas Health and Safety Code section 366.013 (S.B. 1633, 78th Legislature, 2003), and TCEQ, “On-Site Sewage Facility Rules Compilation” (RG-472)