Water hardness in Kladno
3.1 mmol/L very hard
Tap water in Kladno is very hard: 3.1 mmol/L (310 mg/L · 18.1 gpg · 17.4 °dH).
Source: SVAS, Kvalita dodávané pitné vody v roce 2023 (KSKM Kladno) (2023) · data checked 2026-10-23
Kladno is supplied by Vodárny Kladno–Mělník; sources named by the operator include the Mělnická Vrutice groundwater source and the Klíčava reservoir, with water from Prague's Želivka reservoir used as a fallback. Reported hardness is 310.3 mg/L CaCO₃, a figure from 2023 that may have changed. The water is very hard, so heavy limescale on kettles and heating elements is to be expected, and a 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 | 3.1 mmol/L |
|---|---|
| Calcium (mg/L) | 99.9 |
| Magnesium (mg/L) | 14.2 |
| Utility | Středočeské vodárny a.s. (SVAS) / Vodárny Kladno-Mělník (VKM) |
How Kladno compares
- Tap water in Kladno is 158 % harder than the median of the 1516 cities we track in Czechia (1.2 mmol/L).
- By hardness it ranks 216 of 1516 in Czechia (1 = hardest); 86 % of these cities have softer water.
- In Středočeský kraj it is number 1 of 21 cities; the regional median is 0.8 mmol/L.
- Nearest city with clearly softer water: Kutrovice, 14 km away (0.77 mmol/L).
- Nearest city with clearly harder water: Radešín, 22 km away (4.35 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 Kladno
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 17 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| Hoover | S3 |
| 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 Kladno water hard or soft?
It is very hard: 310 mg/L as CaCO₃ (18.1 gpg, 17.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Kladno 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 Kladno water?
18.1 gpg, equal to 17.4 °dH, 31 °fH or 310 mg/L calcium carbonate.
What dishwasher salt setting should I use in Kladno?
For 310 mg/L (17.4 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Kladno?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: SVAS, Kvalita dodávané pitné vody v roce 2023 (KSKM Kladno) (2023). Method: figure published by the water supplier. SVAS, Kvalita dodávané pitné vody v roce 2023 (KSKM Kladno) · Outdated figure? Tell us