Water hardness in Kotka
2.8 °dH soft
Tap water in Kotka is soft: 2.8 °dH (50 mg/L · 2.9 gpg · 5 °fH).
Source: Kymen Vesi, Talousveden laatu 2025 (2025) · data checked 2026-10-22
Kymen Vesi's 2025 water-quality report gives total hardness of 2.8 °dH for the main KyVe network. The same network also serves Pyhtää and former Anjalankoski, and the report prints no Kotka-only split, so this is a network figure rather than a city one. It is very soft water, and limescale builds up slowly.
Finnish waterworks report hardness in °dH; most supplies are soft.
Water data
| Total hardness | 2.8 °dH |
|---|---|
| Utility | Kymen Vesi Oy |
How Kotka compares
- Tap water in Kotka is 19 % softer than the median of the 76 cities we track in Finland (3.5 °dH).
- By hardness it ranks 57 of 76 in Finland (1 = hardest); 23 % of these cities have softer water.
- Nearest city with clearly softer water: Hollola, 98 km away (1.8 °dH).
- Nearest city with clearly harder water: Järvenpää, 102 km away (3.7 °dH).
Ranking of the hardest and softest water in Finland →
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 Kotka
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 3 °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 Kotka water hard or soft?
It is soft: 50 mg/L as CaCO₃ (2.9 gpg, 2.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Kotka safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Finnish waterworks report hardness in °dH; most supplies are soft.
How many grains per gallon is Kotka water?
2.9 gpg, equal to 2.8 °dH, 5 °fH or 50 mg/L calcium carbonate.
What dishwasher salt setting should I use in Kotka?
For 50 mg/L (2.8 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Kotka?
No. With soft water a softener adds nothing.
Source
Source: Kymen Vesi, Talousveden laatu 2025 (2025). Method: figure published by the water supplier. Kymen Vesi, Talousveden laatu 2025 · Outdated figure? Tell us