Hard water is water carrying dissolved calcium and magnesium, picked up as groundwater moves through limestone. Most of the Hudson Valley sits on exactly that geology, so most wells here are hard.
A softener is a tank of resin beads coated in sodium. Hard water flows through, the beads grab the calcium and magnesium and release sodium in exchange. When the resin fills up, the valve draws brine from the salt tank, flushes the hardness down the drain and recharges the beads. That's the regeneration cycle you hear running at 2am.
What it fixes: scale on fixtures and glassware, soap that won't lather, laundry that comes out stiff, and — the expensive one — scale building up inside your water heater, where every millimeter of it costs you efficiency and shortens the tank's life.
Reading your hardness number
| Grains per gallon | Classification |
|---|---|
| Under 1 | soft |
| 1 – 3.5 | slightly hard |
| 3.5 – 7 | moderately hard |
| 7 – 10.5 | hard |
| Over 10.5 | very hard |
Note that 7 gpg is also the ceiling for UV pre-treatment — so if you're above it and you need UV, the softener isn't optional, it's a prerequisite. Labs report hardness either in grains per gallon or ppm; divide ppm by 17.1 to get grains.
Sizing, and why the cheap one costs more
Sizing is arithmetic: people in the house × gallons per person per day × your hardness in grains = grains removed per day. A softener should regenerate roughly every three days. Undersize it and it regenerates constantly, burning salt and water and wearing out the valve. Oversize it badly and the resin sits stagnant between cycles.
Get a metered valve, not a timer. A timer regenerates on a schedule whether you used water or not — including the week you were on vacation. A metered valve counts actual gallons and only regenerates when it needs to. The price difference pays for itself in salt.
What a softener will not do
- It will not remove a rotten-egg smell. Hydrogen sulfide passes straight through the resin.
- It will not kill bacteria. That's UV's job.
- It will not fix bad taste or chlorine. That's carbon.
- It handles only small amounts of iron — meaningful iron needs its own filter upstream or it will foul the resin bed permanently.
- It adds a small amount of sodium. Usually irrelevant, but worth mentioning if someone in the house is on a strict sodium-restricted diet — in which case we leave a hard cold line to the kitchen, or use potassium chloride.