Water hardness in Daegu
75 mg/L moderately hard
Tap water in Daegu is moderately hard: 75 mg/L (4.4 gpg · 4.2 °dH · 7.5 °fH).
Source: K-water / 대구광역시 via data.go.kr (2025) · data checked 2026-10-21
Range across supply zones: 32–98 mg/L.
The municipal treatment plants serving Daegu had a 2025 median hardness of 74.8 mg/L CaCO₃, with plants ranging from 32.0 to 98.0 mg/L. Daegu draws its main supply from the middle Nakdong River. At this level a white film forms on kettles and shower screens, and water heaters collect scale slowly over the years. The spread between plants is wide, so check which plant serves your street.
Korean waterworks report hardness (경도) in mg/L CaCO₃; the drinking-water standard is 300 mg/L (1,000 mg/L for some sources).
Water data
| Total hardness | 75 mg/L |
|---|---|
| Utility | Daegu (대구광역시) |
How Daegu compares
- Tap water in Daegu is 32 % harder than the median of the 127 cities we track in South Korea (57 mg/L).
- By hardness it ranks 32 of 127 in South Korea (1 = hardest); 75 % of these cities have softer water.
- Nearest city with clearly softer water: Goryeong, 30 km away (60 mg/L).
- Nearest city with clearly harder water: Seongju, 28 km away (103 mg/L).
Ranking of the hardest and softest water in South Korea →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Daegu
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 4 °dH |
| AEG / Electrolux | 2 |
| Beko | 1st |
| Hoover | S1 |
| LG | H1 |
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 Daegu water hard or soft?
It is moderately hard: 75 mg/L as CaCO₃ (4.4 gpg, 4.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Daegu safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Korean waterworks report hardness (경도) in mg/L CaCO₃; the drinking-water standard is 300 mg/L (1,000 mg/L for some sources).
How many grains per gallon is Daegu water?
4.4 gpg, equal to 4.2 °dH, 7.5 °fH or 75 mg/L calcium carbonate.
What dishwasher salt setting should I use in Daegu?
For 75 mg/L (4.2 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Daegu?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: K-water / 대구광역시 via data.go.kr (2025). Method: figure published by the water supplier. K-water / 대구광역시 via data.go.kr · Outdated figure? Tell us