You open the dishwasher in your Indianapolis kitchen, and the glasses have spots and a film on them again. Your water is hard: Citizens Energy says it has about 19 grains of hardness per gallon.
Westfield's is even harder, at about 22. Carmel aims for about 8, but its 2025 tests averaged 13.3. Hard water leaves mineral scale inside appliances.
Is Indianapolis water hard or soft?
Hard. Citizens Energy Group runs the water in Indianapolis, and its 2025 report puts the average at 19 grains per gallon.
Grains per gallon is just a unit for hardness. Higher means harder.
Read the exact wording
"Water hardness, expressed at calcium carbonate, averages 320 milligrams per liter, or parts per million (ppm). This equates to 19 grains per gallon… Water hardness can vary depending on the hardness of the source water"
Find your town
| Where you live | Your water utility | Hardness (grains per gallon) |
|---|---|---|
| Indianapolis | Citizens Water | About 19 on average. 8.7 to 27 in 2025 |
| Westfield | Citizens Westfield | About 22 on average. 16 to 29 in 2025 |
| Carmel | Carmel Utilities | Aims for about 8. Its 2025 tests averaged 13.3, with a range of 4 to 37 |
| Fishers | The company on your water bill | Ask that company for your address |
| Zionsville | Citizens Water | Call Citizens at 317-924-3311 for the hardness at your address |
Sources: Citizens' 2025 report, Carmel Utilities' 2025 report and the Town of Zionsville's utilities page.
Indianapolis
The average is about 19 grains. But the 2025 report shows a range from 8.7 all the way up to 27, so your street may not match the average. Hardness can vary by address, and Citizens says to call 317-924-3311 to ask about the typical hardness at yours.
Westfield
Westfield's water comes from Citizens Westfield, part of Citizens Energy Group. It's the hardest average in the table, at about 22 grains, with a range of 16 to 29 in 2025.
Carmel
Carmel runs its own utility, Carmel Utilities, and it aims to soften the water to about 8 grains. Carmel calls that "moderately hard water." But its 2025 tests averaged 13.3, with a range of 4 to 37. Carmel says it may soften less in summer, when people use the most water.
Fishers
The name on your water bill tells you which company you have. Call it and ask for the hardness at your address.
Zionsville
Zionsville gets Citizens Water, the Town says. Call Citizens at 317-924-3311 for the hardness at your address.
How to find your own number
- Find your utility. It's the name on your water bill.
- Call and ask. Citizens customers can call 317-924-3311 and ask for the typical hardness at their address.
- Write it down in grains per gallon. That's the unit Citizens and Carmel both use.
- Keep it with your appliance manuals. You'll want it handy if a tech asks, or if you shop for a softener. If you have one already, here is what to set a water softener to in Indianapolis.
Is 17 gpg considered hard water?
Yes, and it's very hard. The U.S. Geological Survey (USGS) sorts water by how much hardness it holds, in milligrams per liter (mg/L):
- Soft: 0 to 60 mg/L
- Moderately hard: 61 to 120 mg/L
- Hard: 121 to 180 mg/L
- Very hard: more than 180 mg/L
Citizens says its 19 grains equals 320 mg/L. By that math, 17 grains is close to 290 mg/L, which is far past the "very hard" line of 180.
Here's another way to see it. Carmel aims for 8 grains, and Carmel Utilities calls that "moderately hard water." On the USGS scale above, 8 grains is about 137 mg/L, which counts as hard. Seventeen grains is more than twice that.
Why is Indiana water so hard?
Because of the rock it moves through. Hardness is mostly calcium and magnesium, and the USGS says water picks up minerals like these as it moves through soil and rock.
Read the exact wording
"as water moves through soil and rock it dissolves small amounts of naturally-occurring minerals and carries them into the groundwater supply"
A state report looked at ground water in the West Fork White River basin, the area Indianapolis sits in. It found that the calcium and magnesium come from minerals in rock, like calcite and dolomite, that slowly dissolve.
In that report, fewer than 20 percent of the well samples, taken in 1989 and 1990, came in under 180 mg/L.
Read the exact wording
"Calcium and magnesium are the major constituents responsible for hardness in water. Their presence is the result of dissolution of carbonate minerals such as calcite and dolomite." … "Ground water in the West Fork White River basin can be generally characterized as hard to very hard"
From Indiana DNR Division of Water, Ground-Water Resource Availability, West Fork and White River Basin
What does hard water do to dishwashers, washers and ice makers?
It leaves mineral buildup, and it makes soap work less well. You'll see some of it. Some of it you won't.
Dishwashers
Hard water can leave spots or a film on your glasses. Annoying, but harmless. The USGS calls it "hard-water residue," which is "not dangerous, but unsightly."
Washers
With hard water, you need more detergent to get clothes clean, the USGS says. It adds that hard water "can even shorten the life of fabrics and clothes."
GE says hard water can leave limestone build-up in a washer. It forms when the calcium in hard water meets a salt in detergent called sodium carbonate, and GE says a home water softener "will significantly reduce" it.
Ice makers
Minerals can build up as scale inside an ice maker. Whirlpool's cleaning guide for its stand-alone ice makers says minerals left as water freezes "will eventually form a hard, scaly deposit," and with hard water you may need to clean it as often as every 6 months. GE says cloudy cubes from its stand-alone ice makers usually mean scale has built up.
The ice maker in your fridge is a different case. Whirlpool strongly recommends you don't hook its fridge ice makers to softened water, because the salt can harm parts inside.
Water heaters
When hard water heats up, it can leave solid deposits inside the tank. That's scale. The USGS says scale can clog pipes and wear out a water heater sooner, and it can make your water cost more to heat.
Read the exact wording
"When hard water is heated, such as in a home water heater, solid deposits of calcium carbonate can form. This scale can reduce the life of equipment, raise the costs of heating the water, lower the efficiency of electric water heaters, and clog pipes."
The state report agrees that hard water can "cause damaging scale in water heaters, boilers, pipes, and turbines." It also says a water softener can ease many of these problems.
What to write down before you call
Something acting up? Jot these down first.
- Your hardness number, if you've found it.
- The appliance: which one, and about how old it is.
- What you see: for a dishwasher, spots or film on the glasses.
- When it started, and whether it's getting worse.
- A softener: whether you have one, and when it was last serviced.
If an appliance is already clogged or slow, here's how repair calls work on this site.