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Softened water can contain more sodium than the incoming hard water, but its effect on an individual’s blood pressure cannot be predicted from the presence of a softener alone. Total diet, the measured sodium level in the water and personal medical factors all matter.
What the EPA Says About Sodium in Drinking Water
The EPA’s health-effects review found that available studies were not suitable for defining a quantitative relationship between sodium in drinking water and blood pressure. The agency says drinking water is not a significant source of sodium for most people. It advises anyone being treated for sodium-sensitive hypertension to consult a healthcare provider about the sodium level in their water and whether an alternative source or point-of-use treatment is appropriate.
For people prescribed a very low-sodium diet of 500 milligrams per day, the EPA recommends drinking water contain no more than 20 milligrams per liter of sodium. The full context is available in the EPA drinking-water sodium advisory.
Why the Sodium Level Varies
An ion-exchange softener replaces calcium and magnesium with sodium. Harder incoming water generally requires more ion exchange, but equipment settings and household conditions also affect the result. A generic estimate cannot replace a sample from the tap you use for drinking.
The Albuquerque Bernalillo County Water Utility Authority’s 2025 Water Quality Report lists a 29 parts-per-million system-wide sodium average in compliance monitoring and a 22–75 parts-per-million range in special distribution monitoring. A home softener may change that level, so test the treated water rather than assuming the utility result is the final value at your tap.
What to Do if You Limit Sodium
- Ask your healthcare professional for the sodium limit that applies to you.
- Test the cold drinking-water tap after the softener.
- Use an unsoftened kitchen bypass when appropriate, or consider a point-of-use system certified to reduce sodium.
- Maintain any treatment system according to the manufacturer’s instructions.
The CDC explains that reverse osmosis can remove sodium, but certifications and reduction claims differ by model. An appropriate laboratory or sodium test can measure the level at your tap. MicroPure can explain the available reverse-osmosis options; diagnosis and blood-pressure guidance should come from your healthcare professional.