The Pools Scientific Guide to Closing Your Plaster Pool

Plaster is the oldest surface in the Pools Scientific winterizing series, and it's the only one that actually fights back against corrosive water instead of just absorbing damage from it. That single fact makes plaster both the most forgiving pool type to close for winter and the one where getting the chemistry wrong compounds fastest over the years, since the surface itself quietly pays the price every time the water goes hungry.

Inside, you'll find the real chemistry behind plaster's calcium reserve, a genuine buffer built into the material itself, and why that buffer can fail in two opposite directions: etching from corrosive water, and scaling from overcorrecting against it. Real photographs show you exactly what each failure mode looks like, so you know which one you're dealing with before you call anyone. You'll get the complete closing protocol: water chemistry balanced for a target that's a genuine range rather than a simple floor, the correct water level for your specific cover type, the equipment blowout warning that prevents both an injury and a repair bill, and a clear explanation of what an acid wash can and can't fix once damage has already happened. A full closing checklist and quick-reference tables are included for use every season after your first.

Written by John Cooper, a nuclear engineer, U.S. Navy submarine veteran, and the founder of Pools Scientific, a premium pool service platform built on real science rather than industry guesswork.

This is the fourth and final guide in the Pools Scientific winterizing series, above ground, vinyl liner, fiberglass, and plaster pools each get their own dedicated book, since no two pool types hold onto winter the same way.