Water hardness in Koszalin
267 mg/L very hard
Tap water in Koszalin is very hard: 267 mg/L (15.6 gpg · 15 °dH · 26.7 °fH).
Source: MWiK Koszalin, Komunikat o jakości wody I półrocze 2026 (2026) · data checked 2026-10-29
Range across supply zones: 153–381 mg/L.
2 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| mg/L | mg/L | ||
|---|---|---|---|
| Ujęcie Koszalin (uzdatniona) | 381 | 381 | very hard |
| Ujęcie Mostów (uzdatniona) | 153 | 153 | hard |
MWiK Koszalin's first-half 2026 notice covers two zones with a median of 267 mg/L CaCO₃. The range is wide, from 153 to 381 mg/L, so the two zones differ clearly. Check which zone serves your address: the softer end is hard, while the upper end is very hard and will scale heating elements quickly.
Polish suppliers report total hardness in mg/L CaCO₃; the drinking-water regulation range is 60–500 mg/L.
Water data
| Total hardness | 267 mg/L |
|---|---|
| Utility | Miejskie Wodociągi i Kanalizacja Sp. z o.o. Koszalin |
How Koszalin compares
- Tap water in Koszalin is 9 % harder than the median of the 91 cities we track in Poland (245 mg/L).
- By hardness it ranks 28 of 91 in Poland (1 = hardest); 70 % of these cities have softer water.
- In zachodniopomorskie it is number 2 of 5 cities; the regional median is 248 mg/L.
- Nearest city with clearly softer water: Słupsk, 63 km away (208 mg/L).
- Nearest city with clearly harder water: Stargard, 121 km away (425 mg/L).
Ranking of the hardest and softest water in Poland →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Koszalin
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 15 °dH |
| AEG / Electrolux | 4 |
| Beko | 4th |
| Hoover | S2 |
| LG | H3 |
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 Koszalin water hard or soft?
It is very hard: 267 mg/L as CaCO₃ (15.6 gpg, 15 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Koszalin safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Polish suppliers report total hardness in mg/L CaCO₃; the drinking-water regulation range is 60–500 mg/L.
How many grains per gallon is Koszalin water?
15.6 gpg, equal to 15 °dH, 26.7 °fH or 267 mg/L calcium carbonate.
What dishwasher salt setting should I use in Koszalin?
For 267 mg/L (15 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Koszalin?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: MWiK Koszalin, Komunikat o jakości wody I półrocze 2026 (2026). Method: figure published by the water supplier. MWiK Koszalin, Komunikat o jakości wody I półrocze 2026 · Outdated figure? Tell us