Water

Do I need a water softener?

Short answer

That is your choice. A softener replaces lime with sodium and needs maintenance at least once a year. Keep some calcium in the water.

Explanation

With hard water a softener limits limescale. Against that are costs: salt, rinse water, maintenance and pressure loss. In the Netherlands drinking water must keep a hardness of at least 1 mmol/l after softening.

Rules of thumb

• Have the appliance serviced at least once a year. [SW-S35]
• Expect a pressure loss of about 70 kPa (0.7 bar). [SW-S33]
• NL: at least 1 mmol/l hardness after softening (Drinking Water Decree). [SW-S34]

Pitfalls

• If you follow a low-salt diet, take the sodium in softened water into account. [SW-S35]
• Without a non-return valve softened water can flow back into the public network; have a professional install it. [SW-S33]

Search terms

These search terms are in Dutch; only terms that also find a topic in English are links.

waterontharder kalk natrium onderhoud

Read also

• How hard is my water?

Sources

1. SW-S33 Waterhardheid — Dunea (drinkwaterbedrijf) (Reference date 2026-09-27)
2. SW-S34 Praktijkcode hardheid (totaal): calcium en magnesium — Praktijkcodes Drinkwater (NL) (Reference date 2026-09-27)
3. SW-S35 Waterhardheid en ontharding — veelgestelde vragen — De Watergroep (Reference date 2026-09-27)

Reference date: 2026-09-27 · Translated with AI from the Dutch original.