Water hardness in Rumia
283 mg/L very hard
Tap water in Rumia is very hard: 283 mg/L (16.5 gpg · 15.9 °dH · 28.3 °fH).
Source: PEWiK Gdynia – Twardość ogólna (średnia) 2026 r. (2026) · data checked 2026-10-29
Rumia is supplied by PEWiK Gdynia, which publishes an average total hardness of 283 mg/L CaCO₃ for 2026. This is very hard water. Wejherowo, served by the same utility, has a lower published figure, so the value differs from town to town within the PEWiK area. Limescale in kettles and boilers is the practical effect.
Polish suppliers report total hardness in mg/L CaCO₃; the drinking-water regulation range is 60–500 mg/L.
Water data
| Total hardness | 283 mg/L |
|---|---|
| Utility | PEWiK Gdynia Sp. z o.o. |
How Rumia compares
- Tap water in Rumia is 16 % harder than the median of the 91 cities we track in Poland (245 mg/L).
- By hardness it ranks 20 of 91 in Poland (1 = hardest); 79 % of these cities have softer water.
- In pomorskie it is number 2 of 7 cities; the regional median is 220 mg/L.
- Nearest city with clearly softer water: Gdynia, 11 km away (194 mg/L).
- Nearest city with clearly harder water: Grudziądz, 123 km away (359 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 Rumia
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 16 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| 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 Rumia water hard or soft?
It is very hard: 283 mg/L as CaCO₃ (16.5 gpg, 15.9 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Rumia 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 Rumia water?
16.5 gpg, equal to 15.9 °dH, 28.3 °fH or 283 mg/L calcium carbonate.
What dishwasher salt setting should I use in Rumia?
For 283 mg/L (15.9 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Rumia?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: PEWiK Gdynia – Twardość ogólna (średnia) 2026 r. (2026). Method: figure published by the water supplier. PEWiK Gdynia – Twardość ogólna (średnia) 2026 r. · Outdated figure? Tell us