Water hardness in Roudníček
4.7 mmol/L very hard
Tap water in Roudníček is very hard: 4.7 mmol/L (470 mg/L · 27.5 gpg · 26.4 °dH).
Source: SčVK, Moje obec – kvalita vody (aktuální hodnoty) (2026) · data checked 2026-10-21
SčVK reports 470.4 mg/L for Roudníček in the Ústí Region, which is very hard water. The utility's page does not say which source feeds the village, so the cause is not stated here. Expect heavy limescale in kettles, boilers and washing machines, and a descaling routine or softener is worth considering.
Czech suppliers report "Vápník a hořčík" in mmol/L; the recommended range is 2–3.5 mmol/L.
Water data
| Total hardness | 4.7 mmol/L |
|---|---|
| Calcium (mg/L) | 149 |
| Magnesium (mg/L) | 23.8 |
| Utility | Severočeské vodovody a kanalizace, a.s. (SčVK) |
How Roudníček compares
- Tap water in Roudníček is 292 % harder than the median of the 1516 cities we track in Czechia (1.2 mmol/L).
- By hardness it ranks 63 of 1516 in Czechia (1 = hardest); 96 % of these cities have softer water.
- In Ústecký kraj it is number 63 of 631 cities; the regional median is 1.31 mmol/L.
- Nearest city with clearly softer water: Libochovice, 5 km away (2.45 mmol/L).
- Nearest city with clearly harder water: Chotěšov, 6 km away (5.9 mmol/L).
Ranking of the hardest and softest water in Czechia →
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 Roudníček
| Brand | Setting for this water |
|---|---|
| Bosch | H06 |
| Miele | 26 °dH |
| AEG / Electrolux | 6 |
| Beko | 6th |
| Hoover | S4 |
| LG | H4 |
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 Roudníček water hard or soft?
It is very hard: 470 mg/L as CaCO₃ (27.5 gpg, 26.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Roudníček 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 Roudníček water?
27.5 gpg, equal to 26.4 °dH, 47 °fH or 470 mg/L calcium carbonate.
What dishwasher salt setting should I use in Roudníček?
For 470 mg/L (26.4 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Roudníček?
Yes, unless you are only passing through: scale damages appliances within a few years.
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