No Soft Option
In Wimberley, the Fill Water Sets the Rules
Other towns offer city water or a well. Wimberley gives you a well either way. Wimberley Water Supply Corporation and Aqua Texas, which serves Woodcreek, pump from the Trinity Aquifer, and the acreage outside their lines runs on private wells in the same rock. That water tests hard to very hard, commonly 15 to 25 grains, with dissolved solids past 500 ppm, and iron or manganese show up often enough that an untreated fill can leave brown or gray streaks on plaster. Rain tanks are the one exception, and they swing the other way: almost no calcium, almost no alkalinity.
That changes the math on day one. A well fill can put calcium at or above the 200 to 400 ppm ideal range before a single summer of evaporation piles on, so we run the saturation index every week and keep pH toward 7.4 and alkalinity toward the low end of range to hold it near zero. Sequestrant goes in on fill-up and after big top-offs so metals stay dissolved. We shock with liquid chlorine, never cal-hypo, which adds calcium. And because the aquifer drops in dry years, partial drains are planned for cool months and sized to the numbers.
Then there are the creeks. Lots along Cypress Creek and the Blanco sit under cypress and live oak, and needles and leaves acidify water as they rot, dragging alkalinity and pH down while the well fill pushes the other way. Rock-feature and natural-look pools add waterfalls that aerate and raise pH, plus shaded pockets where algae waits. Many Wimberley pools are second homes or short-term rentals: nobody skims between guests, and Friday check-ins arrive with sunscreen and a swim schedule. Add 95 to 100°F afternoons and pool water parked in the mid-80s, and weekly is the floor, not the ceiling.
