Water hardness in Arendal
2 °dH soft
Tap water in Arendal is soft: 2 °dH (36 mg/L · 2.1 gpg · 3.6 °fH).
Source: Arendal kommune, Drikkevannskvalitet (2026) · data checked 2026-10-29
Arendal kommune reports about 35.7 mg/L CaCO₃ for water from the Rore waterworks. That is soft. Agder's bedrock is mostly hard crystalline rock that releases few minerals, though we have not checked the geology around Rore itself. Scale is usually a minor issue here.
Norwegian waterworks report hardness in °dH or mg/L Ca; most supplies are very soft.
Water data
| Total hardness | 2 °dH |
|---|---|
| Utility | Arendal kommune (Rore vannverk) |
How Arendal compares
- Tap water in Arendal is close to the median of the 89 cities we track in Norway (2 °dH).
- By hardness it ranks 45 of 89 in Norway (1 = hardest); 45 % of these cities have softer water.
- In Agder it is number 1 of 4 cities; the regional median is 0.6 °dH.
- Nearest city with clearly softer water: Hægebostad, 91 km away (0.7 °dH).
- Nearest city with clearly harder water: Skien, 96 km away (2.8 °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 Arendal
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 2 °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 Arendal water hard or soft?
It is soft: 36 mg/L as CaCO₃ (2.1 gpg, 2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Arendal 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 Arendal water?
2.1 gpg, equal to 2 °dH, 3.6 °fH or 36 mg/L calcium carbonate.
What dishwasher salt setting should I use in Arendal?
For 36 mg/L (2 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Arendal?
No. With soft water a softener adds nothing.
Source
Source: Arendal kommune, Drikkevannskvalitet (2026). Method: figure published by the water supplier. Arendal kommune, Drikkevannskvalitet · Outdated figure? Tell us