Water hardness in Harderwijk
5.7 °dH moderately hard
Tap water in Harderwijk is moderately hard: 5.7 °dH (102 mg/L · 5.9 gpg · 10.2 °fH).
Source: Vitens, waterhardheid per postcode (2026-10) (2026-10) · data checked 2026-10-19
Range across supply zones: 100–104 mg/L.
Vitens supplies this area, mainly from groundwater, and the sandy ridges of the Veluwe and Utrecht Hills typically give water with comparatively little lime. The reported hardness is 101.7 mg/L CaCO₃, with values from 99.9 to 103.5 mg/L depending on the street. Scale shows on kettles and shower screens over time, but regular descaling usually keeps it manageable.
Dutch suppliers report °dH; most networks are softened centrally to 5.6–8.4 °dH.
Water data
| Total hardness | 5.7 °dH |
|---|
How Harderwijk compares
- Tap water in Harderwijk is 24 % softer than the median of the 654 cities we track in the Netherlands (7.5 °dH).
- By hardness it ranks 613 of 654 in the Netherlands (1 = hardest); 6 % of these cities have softer water.
- In Gelderland it is number 154 of 184 cities; the regional median is 6.7 °dH.
- Nearest city with clearly softer water: Zeewolde, 6 km away (4.5 °dH).
- Nearest city with clearly harder water: Biddinghuizen, 14 km away (7.8 °dH).
Ranking of the hardest and softest water in the Netherlands →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Harderwijk
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 6 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Harderwijk water hard or soft?
It is moderately hard: 102 mg/L as CaCO₃ (5.9 gpg, 5.7 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Harderwijk safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Dutch suppliers report °dH; most networks are softened centrally to 5.6–8.4 °dH.
How many grains per gallon is Harderwijk water?
5.9 gpg, equal to 5.7 °dH, 10.2 °fH or 102 mg/L calcium carbonate.
What dishwasher salt setting should I use in Harderwijk?
For 102 mg/L (5.7 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Harderwijk?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Vitens, waterhardheid per postcode (2026-10) (2026-10). Method: figure published by the water supplier. Vitens, waterhardheid per postcode (2026-10) · Outdated figure? Tell us