How hard is the water in Monroe County, FL?
19.4 grains per gallon
A softener will pay its way here.
The median hardness measured in Monroe County, FL is 332 mg/L as calcium carbonate, which is 19.4 gpg. That is very hard on the USGS scale. It comes from 5 samples at 5 sites between 1998 and 2008, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 17.3 and 22 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 19.4 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 5.2 to 40.3 gpg
The softest single sample on record in Monroe County was 89.6 mg/L and the hardest 690 mg/L, an 8-fold gap. The top quarter of sites read above 22 gpg and the bottom quarter below 17.3 gpg.
Wells 17.3 gpg, rivers and lakes 40.3 gpg
3 groundwater samples from 3 wells put the median at 297 mg/L. 1 surface samples from 1 sites put it at 690 mg/L. In Monroe County the rivers and lakes come out 23.0 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. A utility here that draws from the aquifer can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 32,000-grain unit covers a week between regenerations. Expect about 424 lb of salt a year (11 bags of 40 lb, about $76), 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 $176 a year.
Sizing at 19.4 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,164 | 24,000 | 142 lb |
| 2 | 2,328 | 24,000 | 283 lb |
| 4 | 4,656 | 40,000 | 566 lb |
| 6 | 6,984 | 64,000 | 850 lb |
Monroe County against the rest of Florida
Among the 67 Florida counties with data, Monroe County is number 7 of 67 counting from the hardest. Across the whole country it is harder than 82% of counties.
Softest in Florida: Washington County at 0.3 gpg. Hardest: Sarasota County at 32.2 gpg. Closest to Monroe County: Brevard County (19.6), DeSoto County (19.8), Indian River County (18.9).