Water hardness in Sofia
0.42 mmol/L soft
Tap water in Sofia is soft: 0.42 mmol/L (43 mg/L · 2.5 gpg · 2.4 °dH).
Source: Sofiyska voda, leaflet Kakva voda pieme (table Sredni stoynosti) (2020) · data checked 2026-10-23
This figure is over 3 years old; hardness may have changed.
Sofia receives most of its water from the Iskar reservoir, treated at the Bistritsa plant, with Beli Iskar in the Rila mountains as a complementary source. The reported hardness is 42.5 mg/L CaCO₃. This figure dates from 2020 and may have changed. Kettles and heaters stay fairly clear of scale at this level.
Bulgarian health inspectorates report hardness in mgeq/L (1 mgeq/L = 0.5 mmol/L); the limit is 12 mgeq/L.
Water data
| Total hardness | 0.42 mmol/L |
|---|---|
| Utility | Sofiyska voda AD |
How Sofia compares
- Tap water in Sofia is 66 % softer than the median of the 26 cities we track in Bulgaria (1.26 mmol/L).
- By hardness it ranks 23 of 26 in Bulgaria (1 = hardest); 12 % of these cities have softer water.
- Nearest city with clearly harder water: Saedinenie, 111 km away (2.28 mmol/L).
Ranking of the hardest and softest water in Bulgaria →
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 Sofia
| 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 Sofia water hard or soft?
It is soft: 43 mg/L as CaCO₃ (2.5 gpg, 2.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Sofia safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Bulgarian health inspectorates report hardness in mgeq/L (1 mgeq/L = 0.5 mmol/L); the limit is 12 mgeq/L.
How many grains per gallon is Sofia water?
2.5 gpg, equal to 2.4 °dH, 4.3 °fH or 43 mg/L calcium carbonate.
What dishwasher salt setting should I use in Sofia?
For 43 mg/L (2.4 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Sofia?
No. With soft water a softener adds nothing.
Source
Source: Sofiyska voda, leaflet Kakva voda pieme (table Sredni stoynosti) (2020). Method: figure published by the water supplier. Sofiyska voda, leaflet Kakva voda pieme (table Sredni stoynosti) · Outdated figure? Tell us