Water hardness in Koroseky
0.33 mmol/L soft
Tap water in Koroseky is soft: 0.33 mmol/L (33 mg/L · 1.9 gpg · 1.8 °dH).
Source: ČEVAK a.s. (Veolia), Moje obec – kvalita pitné vody (2026) · data checked 2026-10-21
Koroseky in Jihočeský kraj is supplied by ČEVAK a.s., which reports a hardness of 33.0 mg/L as CaCO₃. That is soft, and low in comparison with most Czech supplies we hold. The source page does not give the origin of the water, so we do not explain it geologically. Scale is minimal, and soft water needs less detergent.
Czech suppliers report "Vápník a hořčík" in mmol/L; the recommended range is 2–3.5 mmol/L.
Water data
| Total hardness | 0.33 mmol/L |
|---|---|
| Calcium (mg/L) | 5 |
| Magnesium (mg/L) | 4.9 |
| Utility | ČEVAK a.s. |
How Koroseky compares
- Tap water in Koroseky is 73 % softer than the median of the 1516 cities we track in Czechia (1.2 mmol/L).
- By hardness it ranks 1478 of 1516 in Czechia (1 = hardest); 2 % of these cities have softer water.
- In Jihočeský kraj it is number 494 of 505 cities; the regional median is 1.2 mmol/L.
- Nearest city with clearly softer water: Keblany, 19 km away (0.25 mmol/L).
- Nearest city with clearly harder water: Černý Dub, 2 km away (1.2 mmol/L).
Ranking of the hardest and softest water in Czechia →
What it means at home
- Little or no limescale in kettles, water heaters or washing machines.
- Soap lathers easily; water does not dry skin or hair.
- Dishwasher: salt setting at minimum or off.
- No softener needed; a jug filter only changes taste.
How much salt will you use for softening?
No. Water this soft does not need softening.
Descale a coffee machine or kettle about every 6 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Koroseky
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 2 °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 Koroseky water hard or soft?
It is soft: 33 mg/L as CaCO₃ (1.9 gpg, 1.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Koroseky 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 Koroseky water?
1.9 gpg, equal to 1.8 °dH, 3.3 °fH or 33 mg/L calcium carbonate.
What dishwasher salt setting should I use in Koroseky?
For 33 mg/L (1.8 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Koroseky?
No. With soft water a softener adds nothing.
Source
Source: ČEVAK a.s. (Veolia), Moje obec – kvalita pitné vody (2026). Method: figure published by the water supplier. ČEVAK a.s. (Veolia), Moje obec – kvalita pitné vody · Outdated figure? Tell us