Why the water here is this hard
Most of Boerne and the surrounding Hill Country draws from the Trinity Aquifer. The water passes through limestone and dolomite, and limestone is largely calcium carbonate — so by the time it reaches a tap it is carrying dissolved calcium and magnesium. Those two minerals are what “hardness” measures.
Anything above 10.5 grains per gallon is classed as very hard. Boerne city water sits comfortably past that, and wells further out sit well past it. This is not a treatment failure or something the utility is doing wrong — it is simply the geology the water travels through.
The signs, in the order people usually notice them
Any one of these on its own means little. Three or more together, and hardness is the common cause.
- Chalky white crust around faucet aerators and showerheads. Usually the first thing anyone sees.
- Cloudy glassware that comes out of the dishwasher already spotted. The detergent is spending itself on calcium instead of on the dishes.
- Soap that will not lather. Shampoo and hand soap seem to vanish without producing suds.
- Stiff, scratchy laundry and towels that stop being soft much sooner than they should.
- Dry skin and dull hair — mineral residue left behind because the rinse never fully rinses.
- Hot water pressure dropping while cold stays fine. That asymmetry points at the heater, not the supply.
- A gas or electric bill creeping up with no change in habits.
Worth knowing
The hot-side-only symptom is the one worth acting on quickly. If hot pressure has fallen off but cold is unchanged, scale has already built up inside the tank or at the outlet — and that is the stage where the heater starts losing years.
What scale does inside a water heater
Calcium comes out of solution when water is heated, and it settles on the hottest surface it can find. In a gas tank that is the bottom — directly over the burner. The layer that forms there behaves like insulation, so the burner has to run longer to move the same amount of heat into the water.
The efficiency loss is the visible part. The damage is the part underneath: the steel at the bottom of the tank now runs hotter than it was designed to, because the scale is holding heat against it. That is what takes years off the tank. On an electric heater the same thing happens on the elements, which is why a scaled electric heater often fails as a dead lower element rather than a leak.
It is also why we would rather size a softener correctly than sell someone a new heater every seven years.
Sizing a softener without guessing
Three numbers decide the size, and it is worth doing the arithmetic rather than buying the box the store stacks highest.
Multiply your household's daily gallons by your hardness, then by seven, to get the capacity you need between regenerations. A four-person Boerne home at 20 grains works out to roughly 42,000 grains — which puts it on a 48,000-grain unit, the next real shelf size up.
Both directions of error cost money. Oversize it and you burn salt regenerating a resin bed that was never exhausted. Undersize it and it cycles too often, which wears the resin out early and gives you hard water at the end of every cycle anyway.
- Hardness in grains per gallon. Boerne city water tests 15-20. Rural Kendall County wells test 25-35. Test rather than assume — wells vary street to street.
- Daily use. Around 75 gallons per person per day is a fair working figure, so a family of four is about 300 gallons.
- Capacity between regenerations. Daily gallons × hardness × 7.
When a softener is not the right answer
A softener removes calcium and magnesium. It does not remove anything else, and on some Hill Country properties something else is the actual complaint.
Iron above roughly 0.3 ppm will foul standard resin, so it needs specialty resin or a pre-filter ahead of the softener — otherwise the softener you just bought stops working within a year or two. Well water carrying sediment needs a pre-filter regardless. And if the complaint is taste or smell rather than scale, that is a filtration question, not a hardness one; softening will not touch it.
This is why we test for iron, pH and total dissolved solids before recommending a unit, rather than after installing one.
If you already have scale
A softener stops new scale forming. It does not remove what is already inside the water heater, and no amount of waiting will.
On a tank heater with a few years of buildup, flushing it is worth doing at the same time as the softener goes in — otherwise you have solved the cause and left the effect sitting in the bottom of the tank. On a heater that is already well into its second decade with heavy scale, the honest answer is usually that the softener protects the next heater. We will tell you that rather than flush a tank that is past saving.
Either way, the order matters: soften first, then deal with what is already there.