How hard is the water in St. Lucie County, FL?
21 grains per gallon
A softener will pay its way here.
The median hardness measured in St. Lucie County, FL is 359 mg/L as calcium carbonate, which is 21 gpg. That is very hard on the USGS scale. It comes from 35 samples at 29 sites between 1999 and 2019, 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 18.8 and 36.4 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: high (how it is measured).
What to do next
At 21 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 14.2 to 248.3 gpg
The softest single sample on record in St. Lucie County was 243 mg/L and the hardest 4,250 mg/L, a 17-fold gap. The top quarter of sites read above 36.4 gpg and the bottom quarter below 18.8 gpg.
Wells 21 gpg, rivers and lakes 13.9 gpg
35 groundwater samples from 29 wells put the median at 359 mg/L. 545 surface samples from 131 sites put it at 237.5 mg/L. In St. Lucie County the wells come out 7.1 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 32,000-grain unit covers a week between regenerations. Expect about 458 lb of salt a year (12 bags of 40 lb, about $82), 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 $182 a year.
Sizing at 21 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,260 | 24,000 | 153 lb |
| 2 | 2,520 | 24,000 | 307 lb |
| 4 | 5,040 | 40,000 | 613 lb |
| 6 | 7,560 | 64,000 | 920 lb |
St. Lucie County against the rest of Florida
Among the 67 Florida counties with data, St. Lucie County is number 4 of 67 counting from the hardest. Across the whole country it is harder than 86% of counties.
Softest in Florida: Washington County at 0.3 gpg. Hardest: Sarasota County at 32.2 gpg. Closest to St. Lucie County: DeSoto County (19.8), Brevard County (19.6), Monroe County (19.4).