Water hardness in Kerava
3.5 °dH moderately hard
Tap water in Kerava is moderately hard: 3.5 °dH (63 mg/L · 3.7 gpg · 6.3 °fH).
Source: Keravan Vesi - Veden laatu (2026) · data checked 2026-10-23
Range across supply zones: 61–64 mg/L.
Finnish waterworks use lake water, often treated or recharged through glacial esker deposits, or natural groundwater. Hardness here is above what the mostly granite bedrock would suggest, so local deposits or the supplier's source are likely to play a role. The reported hardness is 62.5 mg/L CaCO₃, with measurements from 60.7 to 64.3 mg/L. Kettles and shower screens collect some limescale over time, and regular descaling is usually enough.
Finnish waterworks report hardness in °dH; most supplies are soft.
Water data
| Total hardness | 3.5 °dH |
|---|---|
| Utility | Keravan Vesi (City of Kerava water utility) |
How Kerava compares
- Tap water in Kerava is close to the median of the 76 cities we track in Finland (3.5 °dH).
- By hardness it ranks 35 of 76 in Finland (1 = hardest); 52 % of these cities have softer water.
- In 01 it is number 6 of 6 cities; the regional median is 4.2 °dH.
- Nearest city with clearly softer water: Hollola, 70 km away (1.8 °dH).
- Nearest city with clearly harder water: Nurmijärvi, 18 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 Kerava
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 4 °dH |
| AEG / Electrolux | 1 |
| Beko | 1st |
| Hoover | S0 |
| LG | H0 |
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 Kerava water hard or soft?
It is moderately hard: 63 mg/L as CaCO₃ (3.7 gpg, 3.5 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Kerava 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 Kerava water?
3.7 gpg, equal to 3.5 °dH, 6.3 °fH or 63 mg/L calcium carbonate.
What dishwasher salt setting should I use in Kerava?
For 63 mg/L (3.5 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Kerava?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Keravan Vesi - Veden laatu (2026). Method: computed from supplier's calcium and magnesium. Keravan Vesi - Veden laatu · Outdated figure? Tell us