If you live in Yulee or Wildlight, your water typically runs about 12 to 16 grains per gallon — and the utility publishes its figure every year. The 2025 number is 274 parts per million, which is 16 grains per gallon — and the utility’s own label for that is “very hard.”
What “grains per gallon” means
Hardness is dissolved calcium and magnesium. Our water comes from the Floridan aquifer, about a thousand feet down through limestone, so it picks up a lot of both on the way up. Hardness is measured in grains per gallon (gpg). The scale most of the industry uses:
- 0 to 1 gpg — soft
- 1 to 3.5 gpg — slightly hard
- 3.5 to 7 gpg — moderately hard
- 7 to 10.5 gpg — hard
- over 10.5 gpg — very hard
At 16 gpg, we are well into the “very hard” range. For comparison, the JEA grids on the Jacksonville side range from 7 gpg (Cecil, 32065) to 22 gpg (Nocatee, 32081), depending on which plant serves the address. Southside 32256 reads 20.
Why the number doesn’t change much
All three Northeast Florida utilities treat the same way: aeration to knock down the sulfur odor, then chlorination. None of them soften at the plant. That is the mechanical reason the hardness you see at the tap is the hardness of the aquifer, and why it barely moves. JEA’s archived tables for 32034 went from 284 ppm in 2020 to 273 ppm in 2026 — under four percent in six years, less than one grain. What changes a number materially is which plant serves your street, not the year.
What 16 to 19 grains looks like in a house
Hardness is a look-and-feel issue, not a safety issue — JEA says so in its own report, and so do we. What you notice:
- White spotting on dishes, glassware and the shower door, and a film that comes back the day after you clean it.
- Scale inside the water heater, on fixtures and in appliance lines. Tankless heaters are the most sensitive to it.
- Soap that doesn’t lather, and more of it used — in the laundry, the dishwasher and the shower.
- Towels that feel stiff out of the dryer.
The math we do out loud on every call
A softener trades the calcium and magnesium for sodium on a bed of resin, then rinses the resin with salt water on a schedule. How often depends on how many grains come into the house each month. The working rule is 60 gallons per person per day:
16 gpg × 60 gallons × 4 people × 30 days ≈ 115,000 grains a month.
A standard 36,000-grain unit set up correctly regenerates about three times a month on that load, using roughly 9 pounds of salt each time. That is why we size by the household and the published number rather than selling one tank to everybody — and why we tell you the salt cost before you buy, not after.
Not on JEA?
Amelia Island and Fernandina Beach are served by the City of Fernandina Beach and Nassau Amelia Utilities. The city doesn’t print hardness in its annual report, but its water typically runs 270 to 330 ppm — about 16 to 19 grains per gallon, as hard as or harder than the JEA grid. Nassau Amelia Utilities publishes no figure at all. Same aquifer, same treatment — but we don’t quote from a range. We confirm it on your call — and if you’d like to see your exact number, we’ll test it at your sink on install day. Private wells in Callahan, Hilliard, Bryceville and the west county vary house to house, typically 7 to 25 grains or more, often with iron on top. Those always get tested first.