Water hardness in Toyota
11 mg/L soft
Tap water in Toyota is soft: 11 mg/L (0.7 gpg · 0.6 °dH · 1.1 °fH).
Source: Toyota City water quality test results FY2023 (BODIK open data, CC BY 4.0) (2023) · data checked 2026-10-21
Range across supply zones: 2–62 mg/L.
Toyota relies on the Yahagi Dam for about 78% of its water. The utility's 2023 data give 11.3 mg/L CaCO₃ within a range of 2.4 to 62.3 mg/L (may have changed); the spread is wide, so the value at your tap depends on where in the supply area you live. At this level scale is rarely a problem, soap lathers easily and a softener is unnecessary.
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 | 11 mg/L |
|---|---|
| Utility | Toyota City Waterworks |
How Toyota compares
- Tap water in Toyota is 77 % softer than the median of the 228 cities we track in Japan (50 mg/L).
- By hardness it ranks 228 of 228 in Japan (1 = hardest); 0 % of these cities have softer water.
- In Aichi it is number 8 of 8 cities; the regional median is 20 mg/L.
- Nearest city with clearly harder water: Anjō, 15 km away (21 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 Toyota
| 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 Toyota water hard or soft?
It is soft: 11 mg/L as CaCO₃ (0.7 gpg, 0.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Toyota 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 Toyota water?
0.7 gpg, equal to 0.6 °dH, 1.1 °fH or 11 mg/L calcium carbonate.
What dishwasher salt setting should I use in Toyota?
For 11 mg/L (0.6 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Toyota?
No. With soft water a softener adds nothing.
Source
Source: Toyota City water quality test results FY2023 (BODIK open data, CC BY 4.0) (2023). Method: figure published by the water supplier. Toyota City water quality test results FY2023 (BODIK open data, CC BY 4.0) · Outdated figure? Tell us