Water hardness in Tianwei
224 mg/L very hard
Tap water in Tianwei is very hard: 224 mg/L (13.1 gpg · 12.5 °dH · 22.4 °fH).
Source: Taiwan Water Corporation open data (2026) · data checked 2026-10-20
Tianwei is reported by Taiwan Water Corporation at 224.0 mg/L CaCO₃ in 2026 (customer tap water). Surface water cannot meet demand on the Choshui alluvial fan, so groundwater is an important source here, which tends to carry more dissolved minerals. At this level scale builds up quickly in kettles, heaters and shower heads, so a softener or scale protection is worth considering.
Taiwan Water Corporation reports total hardness in mg/L CaCO₃; the drinking-water standard is 300 mg/L.
Water data
| Total hardness | 224 mg/L |
|---|---|
| Utility | Taiwan Water Corporation |
How Tianwei compares
- Tap water in Tianwei is 78 % harder than the median of the 265 cities we track in Taiwan (126 mg/L).
- By hardness it ranks 14 of 265 in Taiwan (1 = hardest); 95 % of these cities have softer water.
- In Changhua County it is number 5 of 23 cities; the regional median is 184 mg/L.
- Nearest city with clearly softer water: Shetou, 7 km away (100 mg/L).
- Nearest city with clearly harder water: Neimen, 106 km away (293 mg/L).
Ranking of the hardest and softest water in Taiwan →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Tianwei
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 13 °dH |
| AEG / Electrolux | 3 |
| Beko | 3rd |
| Hoover | S2 |
| LG | H2 |
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 Tianwei water hard or soft?
It is very hard: 224 mg/L as CaCO₃ (13.1 gpg, 12.5 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Tianwei safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Taiwan Water Corporation reports total hardness in mg/L CaCO₃; the drinking-water standard is 300 mg/L.
How many grains per gallon is Tianwei water?
13.1 gpg, equal to 12.5 °dH, 22.4 °fH or 224 mg/L calcium carbonate.
What dishwasher salt setting should I use in Tianwei?
For 224 mg/L (12.5 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Tianwei?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Taiwan Water Corporation open data (2026). Method: figure published by the water supplier. Taiwan Water Corporation open data · Outdated figure? Tell us