Water hardness in Gjerdrum
1.4 °dH soft
Tap water in Gjerdrum is soft: 1.4 °dH (25 mg/L · 1.5 gpg · 2.5 °fH).
Source: Mattilsynet, Vannverksregisteret – drinking-water analyses (Gjerdrum Kommunale Vannforsyning), NLOD 2.0 (2025) · data checked 2026-10-20
Range across supply zones: 24–26 mg/L.
Gjerdrum Kommunale Vannforsyning reports 25.3 mg/L CaCO₃ for 2025, which is soft. Measurements across the year ran from 24.3 to 26.1 mg/L, so the water is steady. Scale is a minor issue here.
Norwegian waterworks report hardness in °dH or mg/L Ca; most supplies are very soft.
Water data
| Total hardness | 1.4 °dH |
|---|---|
| Utility | Gjerdrum Kommune |
How Gjerdrum compares
- Tap water in Gjerdrum is 29 % softer than the median of the 89 cities we track in Norway (2 °dH).
- By hardness it ranks 58 of 89 in Norway (1 = hardest); 35 % of these cities have softer water.
- In Akershus it is number 3 of 7 cities; the regional median is 1.4 °dH.
- Nearest city with clearly softer water: Lunner, 34 km away (0.6 °dH).
- Nearest city with clearly harder water: Oslo, 24 km away (2.4 °dH).
Ranking of the hardest and softest water in Norway →
What it means at home
- Little or no limescale in kettles, water heaters or washing machines.
- Soap lathers easily; water does not dry skin or hair.
- Dishwasher: salt setting at minimum or off.
- No softener needed; a jug filter only changes taste.
How much salt will you use for softening?
No. Water this soft does not need softening.
Descale a coffee machine or kettle about every 6 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Gjerdrum
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 1 °dH |
| AEG / Electrolux | 1 |
| Beko | 1st |
| Hoover | S0 |
| LG | H0 |
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 Gjerdrum water hard or soft?
It is soft: 25 mg/L as CaCO₃ (1.5 gpg, 1.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Gjerdrum safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Norwegian waterworks report hardness in °dH or mg/L Ca; most supplies are very soft.
How many grains per gallon is Gjerdrum water?
1.5 gpg, equal to 1.4 °dH, 2.5 °fH or 25 mg/L calcium carbonate.
What dishwasher salt setting should I use in Gjerdrum?
For 25 mg/L (1.4 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Gjerdrum?
No. With soft water a softener adds nothing.
Source
Source: Mattilsynet, Vannverksregisteret – drinking-water analyses (Gjerdrum Kommunale Vannforsyning), NLOD 2.0 (2025). Method: figure published by the water supplier. Mattilsynet, Vannverksregisteret – drinking-water analyses (Gjerdrum Kommunale Vannforsyning), NLOD 2.0 · Outdated figure? Tell us