Water hardness in Hradec Králové
2.9 mmol/L very hard
Tap water in Hradec Králové is very hard: 2.9 mmol/L (290 mg/L · 17 gpg · 16.3 °dH).
Source: Královéhradecká provozní, a.s. (KHP) - Kvalita vody page (2026) · data checked 2026-10-21
KHP gives one typical figure for the whole Hradec Králové network, about 2.9 mmol/L or 16 °dH, roughly 290 mg/L CaCO₃. The page also says hardness rises to about 3.5 to 3.9 mmol/L when the Orlice plant is off, so the real value moves between those states. The figure is approximate and the page carries no sampling date. A single February 2026 tap sample of 3.88 mmol/L fits the higher range, but one sample proves little.
Czech suppliers report "Vápník a hořčík" in mmol/L; the recommended range is 2–3.5 mmol/L.
Water data
| Total hardness | 2.9 mmol/L |
|---|---|
| Utility | Královéhradecká provozní, a.s. (KHP) |
How Hradec Králové compares
- Tap water in Hradec Králové is 142 % harder than the median of the 1516 cities we track in Czechia (1.2 mmol/L).
- By hardness it ranks 242 of 1516 in Czechia (1 = hardest); 84 % of these cities have softer water.
- In Královéhradecký kraj it is number 1 of 3 cities; the regional median is 0.41 mmol/L.
- Nearest city with clearly softer water: Chlum, 47 km away (1.81 mmol/L).
- Nearest city with clearly harder water: Všeň, 65 km away (3.73 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 Hradec Králové
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 16 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| Hoover | S2 |
| LG | H3 |
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 Hradec Králové water hard or soft?
It is very hard: 290 mg/L as CaCO₃ (17 gpg, 16.3 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Hradec Králové 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 Hradec Králové water?
17 gpg, equal to 16.3 °dH, 29 °fH or 290 mg/L calcium carbonate.
What dishwasher salt setting should I use in Hradec Králové?
For 290 mg/L (16.3 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Hradec Králové?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Královéhradecká provozní, a.s. (KHP) - Kvalita vody page (2026). Method: figure published by the water supplier. Královéhradecká provozní, a.s. (KHP) - Kvalita vody page · Outdated figure? Tell us