How hard is the water in Hillsborough County, FL?
7.7 grains per gallon
A softener is worth it here.
The median hardness measured in Hillsborough County, FL is 132 mg/L as calcium carbonate, which is 7.7 gpg. That is hard on the USGS scale. It comes from 399 samples at 147 sites between 1990 and 2017, 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 2.8 and 14.2 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
At 7.7 gpg a softener is worth getting, mainly to protect the water heater and cut soap use. Get at least two quotes, ask each installer what grain capacity they are fitting, and check it against the sizing table below. Because Hillsborough County straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on sizing a softener for your household.
From 0.3 to 123.3 gpg
The softest single sample on record in Hillsborough County was 5.6 mg/L and the hardest 2,110 mg/L, a 377-fold gap. The top quarter of sites read above 14.2 gpg and the bottom quarter below 2.8 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 7.7 gpg, rivers and lakes 6.2 gpg
399 groundwater samples from 147 wells put the median at 132 mg/L. 953 surface samples from 134 sites put it at 105.8 mg/L. In Hillsborough County the wells come out 1.5 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. The two sources are close, so the county figure should hold whichever one your tap is on.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 168 lb of salt a year (5 bags of 40 lb, about $30), 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 $130 a year.
Sizing at 7.7 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 462 | 24,000 | 56 lb |
| 2 | 924 | 24,000 | 112 lb |
| 4 | 1,848 | 24,000 | 225 lb |
| 6 | 2,772 | 24,000 | 337 lb |
Hillsborough County against the rest of Florida
Among the 67 Florida counties with data, Hillsborough County is number 44 of 67 counting from the hardest. Across the whole country it is harder than 41% of counties.
Softest in Florida: Washington County at 0.3 gpg. Hardest: Sarasota County at 32.2 gpg. Closest to Hillsborough County: Flagler County (7.8), Hamilton County (8), Osceola County (8.1).