Water hardness in Kure
20 mg/L soft
Tap water in Kure is soft: 20 mg/L (1.2 gpg · 1.1 °dH · 2 °fH).
Source: Kure City Waterworks Bureau, monthly regular water quality tests FY2025 (one-year file) (2025) · data checked 2026-10-21
Range across supply zones: 17–23 mg/L.
Kure's tap water is supplied by Kure City Waterworks Bureau; the intake mix is not confirmed here, but piped water in Hiroshima Prefecture comes mainly from rivers and reservoirs fed by short, steep catchments. The utility's 2025 data give 20.4 mg/L CaCO₃ within a range of 16.5 to 23.2 mg/L. Water this soft rarely leaves scale, so kettles and showerheads stay mostly clear and a softener adds little.
Japanese waterworks report hardness (硬度) in mg/L CaCO₃; the standard is 300 mg/L and the target 10–100 mg/L.
Water data
| Total hardness | 20 mg/L |
|---|---|
| Utility | Kure City Waterworks Bureau |
How Kure compares
- Tap water in Kure is 59 % softer than the median of the 228 cities we track in Japan (50 mg/L).
- By hardness it ranks 217 of 228 in Japan (1 = hardest); 5 % of these cities have softer water.
- In Hiroshima it is number 2 of 3 cities; the regional median is 20 mg/L.
- Nearest city with clearly harder water: Matsuyama, 47 km away (68 mg/L).
Ranking of the hardest and softest water in Japan →
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 Kure
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 1 °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 Kure water hard or soft?
It is soft: 20 mg/L as CaCO₃ (1.2 gpg, 1.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Kure safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Japanese waterworks report hardness (硬度) in mg/L CaCO₃; the standard is 300 mg/L and the target 10–100 mg/L.
How many grains per gallon is Kure water?
1.2 gpg, equal to 1.1 °dH, 2 °fH or 20 mg/L calcium carbonate.
What dishwasher salt setting should I use in Kure?
For 20 mg/L (1.1 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Kure?
No. With soft water a softener adds nothing.
Source
Source: Kure City Waterworks Bureau, monthly regular water quality tests FY2025 (one-year file) (2025). Method: figure published by the water supplier. Kure City Waterworks Bureau, monthly regular water quality tests FY2025 (one-year file) · Outdated figure? Tell us