Water hardness in Pärnu
2.5 mmol/L very hard
Tap water in Pärnu is very hard: 2.5 mmol/L (250 mg/L · 14.6 gpg · 14 °dH).
Source: Terviseamet, veevärkide veeproovid (avalikud andmed) 2021–2025 (2025-10) · data checked 2026-10-19
Range across supply zones: 233–264 mg/L.
Estonia relies largely on groundwater from limestone and dolomite aquifers in the north and sandstone further south, which gives hard water. The reported hardness is 250.2 mg/L CaCO₃, with measurements from 232.6 to 263.8 mg/L. Scale forms fast on heaters and fittings; a water softener is a common remedy.
Estonian laboratories report total hardness (üldkaredus) in mmol/L or mg-eq/L (1 mmol/L = 2 mg-eq/L = 100 mg/L CaCO₃); groundwater supplies are mostly hard.
Water data
| Total hardness | 2.5 mmol/L |
|---|
How Pärnu compares
- Tap water in Pärnu is 8 % harder than the median of the 28 cities we track in Estonia (2.32 mmol/L).
- By hardness it ranks 11 of 28 in Estonia (1 = hardest); 63 % of these cities have softer water.
- Nearest city with clearly softer water: Rapla, 71 km away (1.9 mmol/L).
- Nearest city with clearly harder water: Liiva, 77 km away (3.9 mmol/L).
Ranking of the hardest and softest water in Estonia →
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 Pärnu
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 14 °dH |
| AEG / Electrolux | 3 |
| 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 Pärnu water hard or soft?
It is very hard: 250 mg/L as CaCO₃ (14.6 gpg, 14 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Pärnu safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Estonian laboratories report total hardness (üldkaredus) in mmol/L or mg-eq/L (1 mmol/L = 2 mg-eq/L = 100 mg/L CaCO₃); groundwater supplies are mostly hard.
How many grains per gallon is Pärnu water?
14.6 gpg, equal to 14 °dH, 25 °fH or 250 mg/L calcium carbonate.
What dishwasher salt setting should I use in Pärnu?
For 250 mg/L (14 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Pärnu?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Terviseamet, veevärkide veeproovid (avalikud andmed) 2021–2025 (2025-10). Method: own measurement. Terviseamet, veevärkide veeproovid (avalikud andmed) 2021–2025 · Outdated figure? Tell us