The short answer
A salt-based water softener removes the calcium and magnesium that make water hard. A “salt-free softener” is really a conditioner: the University of Nebraska–Lincoln says these devices “generally” do not remove most of the hardness minerals, but aim to reduce the problems hardness causes (University of Nebraska–Lincoln, Nebraska Water).
So the two are not the same product with and without salt. They do different jobs. Which one fits depends on how hard your water actually is, whether you’re on city water or a well, and what bothers you about it. If you’re not sure hardness is your problem yet, start with the common signs of hard water.
How a salt-based softener works
A softener is an ion exchange unit. Penn State Extension describes a tank of resin coated with sodium ions: as hard water flows through, the resin trades its sodium for calcium and magnesium, and the water leaving the tank is soft (Penn State Extension). The Minnesota Department of Health notes some units use potassium instead of sodium (Minnesota Department of Health).
The resin eventually fills up. The softener then regenerates, flushing a salt solution (brine) back through the resin to carry the calcium and magnesium down the drain (Penn State Extension). That is why you add salt to the brine tank.
Penn State calls the technology “highly developed” and says it works well in most cases to reduce hardness (Penn State Extension). A softener can also take out some iron and manganese: Penn State says colorless, dissolved iron is removed, but iron that has been exposed to air or chlorine will clog the resin, so it should be filtered out first (Penn State Extension). If your well has iron, see iron in well water before choosing anything.
How salt-free conditioners work
UNL groups salt-free devices into four physical technologies (University of Nebraska–Lincoln, Nebraska Water). The one studied most in the research below is template-assisted crystallization (TAC). UNL says TAC uses treated resin beads to “convert (not remove)” dissolved hardness into microscopic crystals that are meant not to stick to surfaces (University of Nebraska–Lincoln, Nebraska Water). EPA WaterSense puts it the same way: instead of removing hardness ions, salt-free conditioners “condition them” to reduce scale buildup (U.S. EPA WaterSense).
Because the calcium and magnesium stay in the water, a hardness test after a salt-free unit reads about the same as before (University of Nebraska–Lincoln, Nebraska Water). In a 2019 University of Waterloo study of a TAC unit, total calcium dropped 2.7% to 4.4% and magnesium 4.0% to 6.9%, reductions the author called “not large enough to be of much practical value” (University of Waterloo). One practical consequence: a WateReuse Research Foundation report noted there was no method to check whether such a device is working “other than observing scale formation” (WateReuse Research Foundation, cosponsored by the Bureau of Reclamation and California State Water Resources Control Board).
Not every salt-free device is equal. UNL says magnetic water treatment “should be regarded as unproven technology” (University of Nebraska–Lincoln, Nebraska Water).
Do salt-free water softeners work?
The honest answer from the research is: some reduce scale, none soften water, and results vary.
- Water heater scale: In the WateReuse report, co-sponsored by the Bureau of Reclamation and California’s State Water Resources Control Board, TAC reduced scale formation in a test water heater by more than 88%, and electromagnetic and electrically induced devices by about 50% (WateReuse Research Foundation, cosponsored by the Bureau of Reclamation and California State Water Resources Control Board). That testing used Arizona waters, and most runs were hotter than a home water heater (WateReuse Research Foundation, cosponsored by the Bureau of Reclamation and California State Water Resources Control Board).
- Spots and soap: The same report did not measure residue on fixtures where water evaporates, because no credible test procedure was identified (WateReuse Research Foundation, cosponsored by the Bureau of Reclamation and California State Water Resources Control Board).
- A second study: The Waterloo thesis found treated water formed “somewhat less scale” than untreated water, and called the difference relatively small (University of Waterloo).
UNL’s summary is fair: these products “offer consumers some promise,” may work very well in one home and disappoint in another, and buyers should check product claims carefully (University of Nebraska–Lincoln, Nebraska Water). EPA WaterSense likewise says evidence suggests “some of these devices” can reduce scale without salt (U.S. EPA WaterSense). If you want the calcium and magnesium actually removed, UNL says an ion exchange softener is the tool for that (University of Nebraska–Lincoln, Nebraska Water).
Sodium, brine and septic systems
Sodium. Penn State says softening with salt “adds 7.5 milligrams per quart for each gpg of hardness removed” (Penn State Extension). UNL gives an example: water with 10 grains per gallon of hardness ends up with about 80 mg/L of sodium (University of Nebraska–Lincoln Extension). The Minnesota Department of Health suggests anyone with a history of high blood pressure ask a doctor about drinking softened water, and lists two ways to cut the added sodium: keep an unsoftened tap for drinking and cooking, or use potassium chloride instead of salt (Minnesota Department of Health). A salt-free conditioner adds no sodium (U.S. EPA WaterSense).
Brine and septic. Penn State estimates about 50 gallons of water per regeneration, which “may or may not” overload a septic system (Penn State Extension). EPA WaterSense says softener discharge can affect septic systems and local water quality, notes some jurisdictions restrict softeners, and advises septic owners to check with the septic manufacturer or a local service provider first (U.S. EPA WaterSense). The Minnesota Department of Health adds that chloride from home softeners passes through wastewater plants and septic systems into lakes and streams (Minnesota Department of Health).
Softeners that regenerate on demand rather than on a timer use less water and salt, according to Penn State and EPA (Penn State Extension) (U.S. EPA WaterSense).
Is your water hard enough to need either?
This is the question to answer first, and on the Grand Strand the answer is often no for city water.
The City of Myrtle Beach says its treated tap water, supplied by Grand Strand Water and Sewer Authority, averages 54 mg/L of hardness, which the City rates as soft on a scale where 0 to 60 mg/L is soft (City of Myrtle Beach). Using Penn State’s conversion of about 17 mg/L per grain, that is roughly 3 grains per gallon, which Penn State’s own scale would call “slightly hard” (17 to 60 mg/L) (Penn State Extension). Penn State says levels below 7.0 gpg “will probably not cause major scaling and soap film” (Penn State Extension), and the Minnesota Department of Health points to softening when hardness is above 7 grains per gallon or 120 mg/L (Minnesota Department of Health).
The Minnesota Department of Health also warns that softening water a utility already delivers soft can cause corrosion in your plumbing (Minnesota Department of Health), and EPA advises against installing a softener when hardness does not indicate a need (U.S. EPA WaterSense). If you’re on Myrtle Beach city water, read our Myrtle Beach water quality report guide before buying anything for hardness.
Private wells are different. EPA notes hard water is most common in areas that rely mainly on groundwater (U.S. EPA WaterSense), and no utility report covers your well, so the only way to know its hardness is to test it (Minnesota Department of Health). Our South Carolina hard water guide covers what to look for.
When each one makes sense
| Salt-based softener | Salt-free conditioner | |
|---|---|---|
| Removes calcium and magnesium | Yes (Penn State Extension) | Not most of it (University of Nebraska–Lincoln, Nebraska Water) |
| Hardness test afterward | Lower (Penn State Extension) | About the same (University of Waterloo) |
| Adds sodium | Yes, unless potassium is used (Minnesota Department of Health) | No (U.S. EPA WaterSense) |
| Brine to drain or septic | About 50 gallons per regeneration (Penn State Extension) | None (U.S. EPA WaterSense) |
| Dissolved iron and manganese | Can reduce (University of Nebraska–Lincoln Extension) | Use ion exchange if you need removal (University of Nebraska–Lincoln, Nebraska Water) |
A salt-based softener tends to fit when a test shows water above 7 grains per gallon (Minnesota Department of Health), when you want fewer mineral spots on glassware and less soap film (Minnesota Department of Health), or when a well also has low levels of dissolved iron (Penn State Extension). Penn State notes you can bypass toilets and outdoor taps, or soften only hot water (Penn State Extension).
A salt-free conditioner may fit when your main concern is scale in the water heater and pipes, when you want no added sodium or brine discharge, or when local rules or a septic system make a softener a poor fit (U.S. EPA WaterSense) (University of Nebraska–Lincoln, Nebraska Water).
And if your water is already soft, the right answer may be neither. See hard water treatment options or how we approach water softeners.
Start with a test
We offer a free in-home water test. It is a screening at your tap, not a laboratory analysis, and it tells you roughly how hard your water is so you can decide whether you need a softener, a conditioner or nothing at all. Penn State Extension recommends an independent lab test if you want a third-party hardness reading (Penn State Extension), and for regulated contaminants such as bacteria, nitrate, lead or arsenic, a certified laboratory test is the way to confirm. You can book a free water test whenever it suits you.
Sources
- Penn State Extension: Water Softening (updated September 8, 2025)
- Minnesota Department of Health: Home Water Softening: Frequently Asked Questions
- University of Nebraska–Lincoln, Nebraska Water: Salt-Free Water “Softener” Alternatives
- University of Nebraska–Lincoln Extension: NebGuide G1491, Drinking Water Treatment: Water Softening (Ion Exchange) (revised September 2014)
- University of Waterloo: Shen, L., Drinking Water Softening/Scale Prevention Technology Assessment and Performance of Template Assisted Crystallization (thesis, 2019)
- WateReuse Research Foundation, cosponsored by the Bureau of Reclamation and California State Water Resources Control Board: Evaluation of Alternatives to Domestic Ion Exchange Water Softeners (2014)
- U.S. EPA WaterSense: Soften Water Without Wasting It, Guide to Selecting and Maintaining a Water-Efficient Water Softener (May 2026)
- U.S. EPA WaterSense: Indoor Features, Water Softeners technical fact sheet (July 2023)
- City of Myrtle Beach: Did you know... That Myrtle Beach’s treated tap water is classified as “soft?” (undated)
Frequently asked questions
Is a salt-free water softener actually a softener?
Not in the usual sense. University of Nebraska–Lincoln Extension says salt-free devices generally do not remove most of the hardness minerals; they aim to reduce scale instead, so a hardness test reads about the same afterward.
Do salt-free water softeners work?
Some reduce scale. In a WateReuse Research Foundation study, a template-assisted crystallization unit cut water heater scale by more than 88%, while a 2019 University of Waterloo study found only somewhat less scale. UNL advises checking product claims carefully.
How much sodium does a water softener add?
Penn State Extension says softening adds 7.5 milligrams of sodium per quart for each grain per gallon of hardness removed. The Minnesota Department of Health suggests an unsoftened drinking tap or potassium chloride to reduce it.
Is a water softener OK with a septic system?
Penn State estimates about 50 gallons of water per regeneration, which may or may not overload a septic system. EPA WaterSense advises checking with your septic manufacturer or a local service provider first.
Do I need a softener on Myrtle Beach city water?
Often not. The City of Myrtle Beach says its tap water averages 54 mg/L of hardness, which it classifies as soft. The Minnesota Department of Health warns that softening already-soft utility water can cause corrosion.
What about well water?
A well’s hardness isn’t published anywhere, so test it. If it is above about 7 grains per gallon or also has dissolved iron, a salt-based softener is the option that actually removes those minerals.