Water hardness in Roudníky
0.68 mmol/L moderately hard
Tap water in Roudníky is moderately hard: 0.68 mmol/L (68 mg/L · 4 gpg · 3.8 °dH).
Source: SčVK, Moje obec – kvalita vody (aktuální hodnoty) (2026) · data checked 2026-10-21
SčVK lists 68.1 mg/L as CaCO₃ for Roudníky in Ústecký kraj (2026), which is moderate. The utility page does not say which source feeds this village, so we do not claim one. At this level scale is a minor nuisance, and a softener is rarely needed.
Czech suppliers report "Vápník a hořčík" in mmol/L; the recommended range is 2–3.5 mmol/L.
Water data
| Total hardness | 0.68 mmol/L |
|---|---|
| Calcium (mg/L) | 24 |
| Magnesium (mg/L) | 2 |
| Utility | Severočeské vodovody a kanalizace, a.s. (SčVK) |
How Roudníky compares
- Tap water in Roudníky is 43 % softer than the median of the 1516 cities we track in Czechia (1.2 mmol/L).
- By hardness it ranks 1285 of 1516 in Czechia (1 = hardest); 15 % of these cities have softer water.
- In Ústecký kraj it is number 547 of 631 cities; the regional median is 1.31 mmol/L.
- Nearest city with clearly softer water: Drahůnky, 8 km away (0.51 mmol/L).
- Nearest city with clearly harder water: Brozánky, 5 km away (2.93 mmol/L).
Ranking of the hardest and softest water in Czechia →
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 Roudníky
| 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 Roudníky water hard or soft?
It is moderately hard: 68 mg/L as CaCO₃ (4 gpg, 3.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Roudníky safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Czech suppliers report "Vápník a hořčík" in mmol/L; the recommended range is 2–3.5 mmol/L.
How many grains per gallon is Roudníky water?
4 gpg, equal to 3.8 °dH, 6.8 °fH or 68 mg/L calcium carbonate.
What dishwasher salt setting should I use in Roudníky?
For 68 mg/L (3.8 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Roudníky?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: SčVK, Moje obec – kvalita vody (aktuální hodnoty) (2026). Method: figure published by the water supplier. SčVK, Moje obec – kvalita vody (aktuální hodnoty) · Outdated figure? Tell us