Water hardness in Star
5.4 gpg moderately hard
Tap water in Star is moderately hard: 5.4 gpg (92 mg/L · 5.2 °dH · 9.2 °fH).
Source: Idaho Drinking Water Watch, chemical sample results, system ID4010220 (2022-01) · data checked 2026-10-19
Range across supply zones: 73–111 mg/L.
This figure is over 3 years old; hardness may have changed.
The figure is for the Star Sewer and Water District, from Idaho's Drinking Water Watch portal. It rests on only 2 samples from 2022: a median of 92.1 mg/L as CaCO3 (5.4 gpg), with a range of 73.2 to 111 mg/L. Two samples are thin evidence. On this data the water is moderately hard.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 5.4 gpg |
|---|---|
| Utility | Star Sewer And Water Dist Water System |
How Star compares
- Tap water in Star is 41 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1055 of 1372 in the United States (1 = hardest); 23 % of these cities have softer water.
- In Idaho it is number 8 of 9 cities; the regional median is 9.4 gpg.
- Nearest city with clearly harder water: Meridian, 13 km away (9.4 gpg).
Ranking of the hardest and softest water in the United States →
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 Star
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 5 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| 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 Star water hard or soft?
It is moderately hard: 92 mg/L as CaCO₃ (5.4 gpg, 5.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Star safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Star water?
5.4 gpg, equal to 5.2 °dH, 9.2 °fH or 92 mg/L calcium carbonate.
What dishwasher salt setting should I use in Star?
For 92 mg/L (5.2 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Star?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Idaho Drinking Water Watch, chemical sample results, system ID4010220 (2022-01). Method: own measurement. Idaho Drinking Water Watch, chemical sample results, system ID4010220 · Outdated figure? Tell us