How hard is the water in Lake of the Woods County, MN?

3.1 grains per gallon

You do not need a softener here.

The median hardness measured in Lake of the Woods County, MN is 53 mg/L as calcium carbonate, which is 3.1 gpg. That is soft on the USGS scale. It comes from 101 samples at 14 sites between 1991 and 2024, drawn from every sampling site in the county, wells and surface water together.

How much it varies here

Half the sites came in between 2.5 and 7.8 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

You can skip the softener. At 3.1 gpg the most a softener would fix is the odd water spot. If a salesperson in Lake of the Woods County says otherwise, ask to see their reading in grains per gallon and compare it with this one. Because Lake of the Woods 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 2.0 to 13.0 gpg

The softest single sample on record in Lake of the Woods County was 35 mg/L and the hardest 222 mg/L, a 6-fold gap. The top quarter of sites read above 7.8 gpg and the bottom quarter below 2.5 gpg. So even in a soft county, a handful of wells here produce water hard enough to scale a heater.

Lake of the Woods County against the rest of Minnesota

Among the 87 Minnesota counties with data, Lake of the Woods County is number 85 of 87 counting from the hardest. Across the whole country it is harder than 22% of counties.

Softest in Minnesota: Lake County at 1.3 gpg. Hardest: Traverse County at 42.6 gpg. Closest to Lake of the Woods County: Pine County (3.3), Koochiching County (2.7), Cook County (3.7).