Water hardness in Prešov
2.74 mmol/L very hard
Tap water in Prešov is very hard: 2.74 mmol/L (274 mg/L · 16 gpg · 15.4 °dH).
Source: Východoslovenská vodárenská spoločnosť (VVS) (2025) · data checked 2026-10-20
Range across supply zones: 144–369 mg/L.
VVS supplies this town; the Starina reservoir is the main surface source of its wider system, and many schemes also rely on local wells and springs. The reported hardness is 274.2 mg/L CaCO₃, with measurements from 144.1 to 369.3 mg/L. Appliances scale up quickly at this level, and a softener is worth considering.
Slovak suppliers report "Vápnik a horčík" in mmol/L; the recommended range is 1.1–5 mmol/L.
Water data
| Total hardness | 2.74 mmol/L |
|---|---|
| Utility | Východoslovenská vodárenská spoločnosť (VVS) |
How Prešov compares
- Tap water in Prešov is 44 % harder than the median of the 1113 cities we track in Slovakia (1.9 mmol/L).
- By hardness it ranks 344 of 1113 in Slovakia (1 = hardest); 69 % of these cities have softer water.
- In Prešov Region it is number 94 of 266 cities; the regional median is 2.22 mmol/L.
- Nearest city with clearly softer water: Teriakovce, 6 km away (1.37 mmol/L).
- Nearest city with clearly harder water: Veľký Šariš, 5 km away (4.91 mmol/L).
Ranking of the hardest and softest water in Slovakia →
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 Prešov
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 15 °dH |
| AEG / Electrolux | 4 |
| Beko | 4th |
| 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 Prešov water hard or soft?
It is very hard: 274 mg/L as CaCO₃ (16 gpg, 15.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Prešov safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Slovak suppliers report "Vápnik a horčík" in mmol/L; the recommended range is 1.1–5 mmol/L.
How many grains per gallon is Prešov water?
16 gpg, equal to 15.4 °dH, 27.4 °fH or 274 mg/L calcium carbonate.
What dishwasher salt setting should I use in Prešov?
For 274 mg/L (15.4 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Prešov?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Východoslovenská vodárenská spoločnosť (VVS) (2025). Method: figure published by the water supplier. Východoslovenská vodárenská spoločnosť (VVS) · Outdated figure? Tell us