Water hardness in Riihimäki
4 °dH moderately hard
Tap water in Riihimäki is moderately hard: 4 °dH (72 mg/L · 4.2 gpg · 7.2 °fH).
Source: Riihimäen Vesi, Verkoston laatu 2025 (network water quality by area), Kokonaiskovuus (2025) · data checked 2026-10-22
Range across supply zones: 66–100 mg/L.
4 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| °dH | mg/L | ||
|---|---|---|---|
| Kaupungin eteläinen osa (south part of city) | 5.6 | 100 | moderately hard |
| Kaupungin itäinen osa (east part of city) | 3.7 | 66 | moderately hard |
| Kaupungin läntinen osa (west part of city) | 4 | 72 | moderately hard |
| Kaupungin pohjoinen osa ja keskusta-alue vesitornin eteläpuolella (north part and centre south of water tower) | 4 | 71 | moderately hard |
Riihimäen Vesi publishes its 2025 network results by area. The north and centre read 0.71 mmol/L, the east 0.66 and the west 0.72, all soft. The southern part of the city is harder at 1.0 mmol/L, which the utility calls medium hard. The table gives a year but no measurement period.
Finnish waterworks report hardness in °dH; most supplies are soft.
Water data
| Total hardness | 4 °dH |
|---|---|
| Utility | Riihimäen Vesi (Riihimäki city water utility) |
How Riihimäki compares
- Tap water in Riihimäki is 16 % harder than the median of the 76 cities we track in Finland (3.5 °dH).
- By hardness it ranks 29 of 76 in Finland (1 = hardest); 63 % of these cities have softer water.
- Nearest city with clearly softer water: Hollola, 49 km away (1.8 °dH).
- Nearest city with clearly harder water: Nurmijärvi, 30 km away (5.1 °dH).
Ranking of the hardest and softest water in Finland →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Riihimäki
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 4 °dH |
| AEG / Electrolux | 2 |
| Beko | 1st |
| Hoover | S1 |
| LG | H1 |
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 Riihimäki water hard or soft?
It is moderately hard: 72 mg/L as CaCO₃ (4.2 gpg, 4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Riihimäki safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Finnish waterworks report hardness in °dH; most supplies are soft.
How many grains per gallon is Riihimäki water?
4.2 gpg, equal to 4 °dH, 7.2 °fH or 72 mg/L calcium carbonate.
What dishwasher salt setting should I use in Riihimäki?
For 72 mg/L (4 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Riihimäki?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Riihimäen Vesi, Verkoston laatu 2025 (network water quality by area), Kokonaiskovuus (2025). Method: figure published by the water supplier. Riihimäen Vesi, Verkoston laatu 2025 (network water quality by area), Kokonaiskovuus · Outdated figure? Tell us