Water hardness in Frederikshavn
9 °dH hard
Tap water in Frederikshavn is hard: 9 °dH (161 mg/L · 9.4 gpg · 16.1 °fH).
Source: GEUS, Drikkevandets hårdhed i Danmark (Jupiter database), CC BY 4.0 (2023) · data checked 2026-10-19
All of Denmark's tap water is groundwater, and in North Jutland it comes partly from chalk and limestone aquifers and partly from sand aquifers. The GEUS-reported hardness is 160.6 mg/L CaCO₃. Kettles, shower heads and washing machine heating elements scale up noticeably, so regular descaling is worthwhile.
Danish waterworks report hardness in °dH; GEUS classes: soft < 8, medium hard 8–12, fairly hard 12–18, hard 18–30, very hard > 30 °dH. Most Danish tap water is groundwater and hard.
Water data
| Total hardness | 9 °dH |
|---|
How Frederikshavn compares
- Tap water in Frederikshavn is 40 % softer than the median of the 388 cities we track in Denmark (14.9 °dH).
- By hardness it ranks 332 of 388 in Denmark (1 = hardest); 13 % of these cities have softer water.
- In North Denmark it is number 38 of 49 cities; the regional median is 10.8 °dH.
- Nearest city with clearly softer water: Byrum, 34 km away (5.3 °dH).
- Nearest city with clearly harder water: Sindal, 20 km away (11.7 °dH).
Ranking of the hardest and softest water in Denmark →
What it means at home
- Fast scale on taps, shower screens and kettle; white spots on glassware.
- Water heater: efficiency loss and element failures within years if unprotected.
- Dry skin and dull hair after showering are common.
- Softener recommended; jug or reverse osmosis for drinking.
How much salt will you use for softening?
Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.
Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Frederikshavn
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 9 °dH |
| AEG / Electrolux | 2 |
| Beko | 3rd |
| Hoover | S1 |
| LG | H2 |
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 Frederikshavn water hard or soft?
It is hard: 161 mg/L as CaCO₃ (9.4 gpg, 9 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Frederikshavn safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Danish waterworks report hardness in °dH; GEUS classes: soft < 8, medium hard 8–12, fairly hard 12–18, hard 18–30, very hard > 30 °dH. Most Danish tap water is groundwater and hard.
How many grains per gallon is Frederikshavn water?
9.4 gpg, equal to 9 °dH, 16.1 °fH or 161 mg/L calcium carbonate.
What dishwasher salt setting should I use in Frederikshavn?
For 161 mg/L (9 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Frederikshavn?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: GEUS, Drikkevandets hårdhed i Danmark (Jupiter database), CC BY 4.0 (2023). Method: figure published by the water supplier. GEUS, Drikkevandets hårdhed i Danmark (Jupiter database), CC BY 4.0 · Outdated figure? Tell us