How hard is the water in Linn County, MO?
5.1 grains per gallon
Optional: a softener helps, but plenty of homes skip it.
The median hardness measured in Linn County, MO is 88 mg/L as calcium carbonate, which is 5.1 gpg. That is moderately hard on the USGS scale. It comes from 137 samples at 13 sites between 2007 and 2026, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 3.4 and 10.1 gpg. That spread crosses a decision line, so some homes here land on a different answer. A $10 test strip on your own tap settles it. Confidence in the county figure: high (how it is measured).
What to do next
At 5.1 gpg this is your call. Look for white film on glasses and crust on the shower head: if you see little of either, you can live without one. If you do want one, a 24,000-grain unit is enough, so ask for that size rather than a bigger one. Because Linn County straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on when a softener is not worth it.
From 2.1 to 13.1 gpg
The softest single sample on record in Linn County was 36.8 mg/L and the hardest 224 mg/L, a 6-fold gap. The top quarter of sites read above 10.1 gpg and the bottom quarter below 3.4 gpg.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 112 lb of salt a year (3 bags of 40 lb, about $20), and roughly 2,346 gallons of regeneration water. Installed, most units run $1,000 to $4,500; spread over 15 years with salt, that is about $120 a year.
Sizing at 5.1 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 306 | 24,000 | 37 lb |
| 2 | 612 | 24,000 | 74 lb |
| 4 | 1,224 | 24,000 | 149 lb |
| 6 | 1,836 | 24,000 | 223 lb |
Linn County against the rest of Missouri
Among the 110 Missouri counties with data, Linn County is number 108 of 110 counting from the hardest. Across the whole country it is harder than 31% of counties.
Softest in Missouri: Livingston County at 4.1 gpg. Hardest: Reynolds County at 96.7 gpg. Closest to Linn County: Andrew County (5.1), Pemiscot County (5.7), Chariton County (5.8).