How hard is the water in Florence County, SC?
0.5 grains per gallon
You do not need a softener here.
The median hardness measured in Florence County, SC is 8 mg/L as calcium carbonate, which is 0.5 gpg. That is soft on the USGS scale. It comes from 25 samples at 14 sites between 1990 and 2026, 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 0.2 and 1.5 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
You can skip the softener. At 0.5 gpg the most a softener would fix is the odd water spot. If a salesperson in Florence County says otherwise, ask to see their reading in grains per gallon and compare it with this one.
More on when a softener is not worth it.
From 0.1 to 2.3 gpg
The softest single sample on record in Florence County was 1.9 mg/L and the hardest 39.5 mg/L, a 21-fold gap. The top quarter of sites read above 1.5 gpg and the bottom quarter below 0.2 gpg.
Wells 0.5 gpg, rivers and lakes 1.3 gpg
25 groundwater samples from 14 wells put the median at 7.9 mg/L. 459 surface samples from 36 sites put it at 22 mg/L. In Florence County the rivers and lakes come out 0.8 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. The two sources are close, so the county figure should hold whichever one your tap is on.
Florence County against the rest of South Carolina
Among the 46 South Carolina counties with data, Florence County is number 37 of 46 counting from the hardest. Across the whole country it is harder than 2% of counties.
Softest in South Carolina: Aiken County at 0.2 gpg. Hardest: Georgetown County at 15.2 gpg. Closest to Florence County: Chesterfield County (0.5), Marlboro County (0.4), Pickens County (0.5).