Water hardness in Indianapolis
18.5 gpg very hard
Tap water in Indianapolis is very hard: 18.5 gpg (317 mg/L · 17.8 °dH · 31.7 °fH).
Source: Citizens Energy Group 2025 Drinking Water Report, Indianapolis and Morgan County system (2025) · data checked 2026-10-19
Range across supply zones: 148–460 mg/L.
Citizens Energy Group reports an average of 317 mg/L (18.5 gpg) for the Indianapolis and Morgan County system in 2025. Samples ranged from 148 to 460 mg/L, so water here is very hard. Westfield and Westfield-South Madison are separate Citizens service areas and are not part of this figure. Scale builds fast, and a softener is worth considering.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 18.5 gpg |
|---|---|
| Utility | Citizens Energy Group |
How Indianapolis compares
- Tap water in Indianapolis is 104 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 204 of 1372 in the United States (1 = hardest); 85 % of these cities have softer water.
- In Indiana it is number 25 of 40 cities; the regional median is 20 gpg.
- Nearest city with clearly softer water: Carmel, 24 km away (13.3 gpg).
- Nearest city with clearly harder water: Fishers, 24 km away (23.5 gpg).
Ranking of the hardest and softest water in the United States →
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 Indianapolis
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 18 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| Hoover | S3 |
| LG | H3 |
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 Indianapolis water hard or soft?
It is very hard: 317 mg/L as CaCO₃ (18.5 gpg, 17.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Indianapolis 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 Indianapolis water?
18.5 gpg, equal to 17.8 °dH, 31.7 °fH or 317 mg/L calcium carbonate.
What dishwasher salt setting should I use in Indianapolis?
For 317 mg/L (17.8 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Indianapolis?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Citizens Energy Group 2025 Drinking Water Report, Indianapolis and Morgan County system (2025). Method: own measurement. Citizens Energy Group 2025 Drinking Water Report, Indianapolis and Morgan County system · Outdated figure? Tell us