How hard is the water in Knox County, OH?
18.8 grains per gallon
A softener will pay its way here.
The median hardness measured in Knox County, OH is 323 mg/L as calcium carbonate, which is 18.8 gpg. That is very hard on the USGS scale. It comes from 19 samples at 6 sites between 1995 and 2024, drawn from groundwater wells, which is what most taps and private wells in the county draw on.
How much it varies here
Half the sites came in between 15.3 and 19.4 gpg. The whole middle of that range gives the same answer, so a test of your own tap is unlikely to change it. Confidence in the county figure: medium (how it is measured).
What to do next
At 18.8 gpg a softener pays its way here. Before you buy, check the quoted unit's grain capacity against the sizing table below, and ask whether it regenerates on demand, which uses less salt than a timer. Call your utility for its own report if you are on city water.
More on sizing a softener for your household.
From 11.2 to 20.0 gpg
The softest single sample on record in Knox County was 192 mg/L and the hardest 342.5 mg/L, a 2-fold gap. The top quarter of sites read above 19.4 gpg and the bottom quarter below 15.3 gpg.
Wells 18.8 gpg, rivers and lakes 12.3 gpg
19 groundwater samples from 6 wells put the median at 322.5 mg/L. 669 surface samples from 31 sites put it at 210 mg/L. In Knox County the wells come out 6.5 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. A utility here that draws from the river can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 411 lb of salt a year (11 bags of 40 lb, about $74), 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 $174 a year.
Sizing at 18.8 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,128 | 24,000 | 137 lb |
| 2 | 2,256 | 24,000 | 274 lb |
| 4 | 4,512 | 32,000 | 549 lb |
| 6 | 6,768 | 48,000 | 823 lb |
Knox County against the rest of Ohio
Among the 88 Ohio counties with data, Knox County is number 40 of 88 counting from the hardest. Across the whole country it is harder than 81% of counties.
Softest in Ohio: Scioto County at 5.7 gpg. Hardest: Perry County at 113.3 gpg. Closest to Knox County: Huron County (18.8), Williams County (19), Portage County (19).