How Much Sodium Does Softened Water Actually Add?
Take the hardness of your water in grains per gallon and multiply by 8. That is roughly how many milligrams of sodium per litre softening adds [1][2]. Water at 10 grains comes out around 80 mg/L; at 20 grains, around 160 mg/L. It is sodium, not salt, and it is a number you can decide about instead of guess at.
The number, and where it comes from
Softening works by trading hardness for sodium: calcium and magnesium stay on the resin, sodium leaves with the water. So the amount of sodium added is not a brand question or a setting — it is arithmetic on your hardness.
Two university extension publications give the same figure. Nebraska: sodium is added "at a rate of about 8 mg/L for each grain per gallon (gpg) of hardness", and water at 10 gpg finishes at about 80 mg/L [1]. North Dakota State says the same: "for every grain of hardness removed from water, about 8 mg/1 (ppm) of sodium is added" [2].
That is why the first thing worth knowing is your own hardness number, from a test rather than from a neighbour.
- 5 grains → about 40 mg/L of sodium
- 10 grains → about 80 mg/L
- 15 grains → about 120 mg/L
- 20 grains → about 160 mg/L
Is that a lot?
That depends entirely on the person, and it is a question for a doctor rather than for a plumber. Both publications say the same thing in the same tone: people on sodium-restricted diets should account for the sodium that softening adds and discuss it with their physician [1][2].
What we can tell you is the plumbing side: the sodium arrives in every softened tap, including the kitchen one, unless the system was built so that it does not.
Three ways to change the number
Leave a tap unsoftened. The simplest answer, and the one we fit most often: the cold line to the kitchen sink is taken off before the softener, so drinking and cooking water never sees it.
Use potassium chloride instead of sodium chloride. NDSU notes it can be substituted for health or environmental reasons, but that it costs more, clings more strongly to the resin, and needs roughly 10% more per regeneration [2].
Add a drinking-water unit. A reverse-osmosis system at the kitchen reduces sodium along with much else — the CDC lists sodium among what reverse osmosis removes [3].
- Unsoftened kitchen tap — cheapest, no consumables
- Potassium chloride — no plumbing change, higher running cost
- Reverse osmosis at the sink — best water for drinking, needs a drain and a little cabinet space
What this means in Tampa Bay
Our water is hard enough that softeners are ordinary equipment here, and well water in Pasco and Hernando is often harder than city water — so the sodium figure lands higher on a well than on a municipal supply.
Get the hardness number first. Everything on this page follows from it, and it also decides how much salt the softener will use in a year. We test, we fit the unsoftened kitchen line when you want one, and we install drinking-water systems.
A water test takes fifteen minutes and settles this, the salt usage and the equipment size at once.
Call 727-470-7126FAQ
Does softened water taste salty?
It should not. Sodium at these levels is not a taste most people notice; a salty taste points at a fault in the valve, not at normal operation.
How do I find my hardness in grains?
A test. Utilities publish an average in their annual report, but on a well, and even between neighbourhoods, it varies — and this number is worth having right.
Is softened water safe to cook with?
For most people, yes. If someone in the house is on a sodium-restricted diet, the usual answer here is an unsoftened cold tap at the kitchen sink, which costs very little to fit during installation.
Does a softener remove anything else I should know about?
It reduces some iron and manganese along with hardness. It does not filter sediment, chlorine or sulfur — those need their own stage.
Is potassium chloride better?
It is different, not better. It avoids the sodium, costs more per bag and needs about 10% more per regeneration, as NDSU notes.
Sources
We review and cite. We do not reproduce a paper or a manual — follow the links for the originals.
- [1]Drinking Water Treatment: Water Softening (Ion Exchange), G1491 — Sharon O. Skipton, Bruce I. Dvorak · University of Nebraska–Lincoln Extension · revised 2014University extension · 8 mg/L sodium per grain; the 10 gpg → 80 mg/L example
- [2]Water Softening (Ion Exchange), WQ1031 — Tom Scherer, Roxanne Johnson · NDSU Extension · revised 2022University extension · same sodium figure; potassium chloride trade-offs
- [3]About Home Water Treatment Systems — US Centers for Disease Control and PreventionGovernment or standards body · what reverse osmosis reduces, sodium included
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