Water hardness in Gniezno
362 mg/L very hard
Tap water in Gniezno is very hard: 362 mg/L (21.1 gpg · 20.3 °dH · 36.1 °fH).
Source: PWiK Gniezno – Okresowe parametry jakości wody (2026) · data checked 2026-10-29
Range across supply zones: 299–424 mg/L.
2 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| mg/L | mg/L | ||
|---|---|---|---|
| SUW Sosnowa | 299 | 299 | very hard |
| SUW Żwirki i Wigury | 424 | 424 | very hard |
PWiK Gniezno publishes periodic water parameters for two zones. The median is 361.5 mg/L CaCO₃ with a range of 299 to 424 mg/L, which is very hard everywhere in the city. Scale forms fast in hot-water systems at this level, so regular descaling or a softener on the main supply is common.
Polish suppliers report total hardness in mg/L CaCO₃; the drinking-water regulation range is 60–500 mg/L.
Water data
| Total hardness | 362 mg/L |
|---|---|
| Utility | PWiK Gniezno |
How Gniezno compares
- Tap water in Gniezno is 48 % harder than the median of the 91 cities we track in Poland (245 mg/L).
- By hardness it ranks 7 of 91 in Poland (1 = hardest); 93 % of these cities have softer water.
- In wielkopolskie it is number 1 of 5 cities; the regional median is 320 mg/L.
- Nearest city with clearly softer water: Konin, 57 km away (269 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 Gniezno
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 20 °dH |
| AEG / Electrolux | 5 |
| Beko | 6th |
| Hoover | S3 |
| 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 Gniezno water hard or soft?
It is very hard: 362 mg/L as CaCO₃ (21.1 gpg, 20.3 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Gniezno 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 Gniezno water?
21.1 gpg, equal to 20.3 °dH, 36.1 °fH or 362 mg/L calcium carbonate.
What dishwasher salt setting should I use in Gniezno?
For 362 mg/L (20.3 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Gniezno?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: PWiK Gniezno – Okresowe parametry jakości wody (2026). Method: figure published by the water supplier. PWiK Gniezno – Okresowe parametry jakości wody · Outdated figure? Tell us