Water hardness in Kose
2.15 mmol/L very hard
Tap water in Kose is very hard: 2.15 mmol/L (215 mg/L · 12.6 gpg · 12.1 °dH).
Source: Terviseamet, veevärkide veeproovid (avalikud andmed) 2021–2025 (2025-05) · data checked 2026-10-20
Range across supply zones: 210–220 mg/L.
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 | 2.15 mmol/L |
|---|
How Kose compares
- Tap water in Kose is 8 % softer than the median of the 28 cities we track in Estonia (2.32 mmol/L).
- By hardness it ranks 16 of 28 in Estonia (1 = hardest); 41 % of these cities have softer water.
- In Harjumaa it is number 5 of 11 cities; the regional median is 2.02 mmol/L.
- Nearest city with clearly softer water: Saku, 32 km away (1.2 mmol/L).
- Nearest city with clearly harder water: Peetri, 31 km away (3.4 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 Kose
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 12 °dH |
| AEG / Electrolux | 3 |
| Beko | 3rd |
| Hoover | S2 |
| LG | H2 |
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 Kose water hard or soft?
It is very hard: 215 mg/L as CaCO₃ (12.6 gpg, 12.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Kose 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 Kose water?
12.6 gpg, equal to 12.1 °dH, 21.5 °fH or 215 mg/L calcium carbonate.
What dishwasher salt setting should I use in Kose?
For 215 mg/L (12.1 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Kose?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Terviseamet, veevärkide veeproovid (avalikud andmed) 2021–2025 (2025-05). Method: own measurement. Terviseamet, veevärkide veeproovid (avalikud andmed) 2021–2025 · Outdated figure? Tell us