Water hardness in Mito
56 mg/L soft
Tap water in Mito is soft: 56 mg/L (3.3 gpg · 3.1 °dH · 5.6 °fH).
Source: Mito City Waterworks, tap-water quality results FY2025 (令和7年度 水道水質検査結果, 末端水) (2025) · data checked 2026-11-05
Range across supply zones: 46–64 mg/L.
Mito City Waterworks publishes monthly FY2025 results from eight end-of-network taps, one for each distribution system. The tap averages sit close together, and the 56 mg/L shown is their median, with individual monthly readings between 46 and 64 mg/L. Because every tap reads in a narrow band, hardness here changes little from one part of the city to another. The published results do not describe the underlying water sources, so this note does not either.
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 | 56 mg/L |
|---|---|
| Utility | 水戸市上下水道局水道部 Mito City Waterworks |
How Mito compares
- Tap water in Mito is 12 % harder than the median of the 228 cities we track in Japan (50 mg/L).
- By hardness it ranks 94 of 228 in Japan (1 = hardest); 59 % of these cities have softer water.
- In Ibaraki it is number 2 of 3 cities; the regional median is 56 mg/L.
- Nearest city with clearly softer water: Hitachi, 33 km away (36 mg/L).
- Nearest city with clearly harder water: Tsukuba, 42 km away (82 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 Mito
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 3 °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 Mito water hard or soft?
It is soft: 56 mg/L as CaCO₃ (3.3 gpg, 3.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Mito 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 Mito water?
3.3 gpg, equal to 3.1 °dH, 5.6 °fH or 56 mg/L calcium carbonate.
What dishwasher salt setting should I use in Mito?
For 56 mg/L (3.1 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Mito?
No. With soft water a softener adds nothing.
Source
Source: Mito City Waterworks, tap-water quality results FY2025 (令和7年度 水道水質検査結果, 末端水) (2025). Method: figure published by the water supplier. Mito City Waterworks, tap-water quality results FY2025 (令和7年度 水道水質検査結果, 末端水) · Outdated figure? Tell us