BioGuard Lo 'N Slo 3 lb. | Pool pH Reducer

BioGuard Lo 'N Slo is a granular pH and total alkalinity reducer built around a simple proposition: you should not have to keep a jug of muriatic acid in your garage to run a swimming pool.

Muriatic acid works. It also fumes when the cap comes off, corrodes nearby metal from across the shelf, splashes when poured, and burns skin on contact. Lo 'N Slo delivers the same correction as a dry granule that pours out of a container without a plume of vapor, doesn't attack the tools stored next to it, and doesn't turn a dropped bottle into an emergency. For most pool owners that trade is worth making on its own — before considering that the results are easier to control.

The job it does is one of the most frequently needed in pool care. pH drifts upward on its own in nearly every pool. Aeration from water features, fountains, and returns drives carbon dioxide out of the water and pushes pH up. Fresh fill water is often alkaline to begin with. Salt chlorine generators raise pH continuously as a byproduct of how they produce chlorine. Left alone, high pH means cloudy water, scale forming on surfaces and heater elements, and chlorine that tests fine but sanitizes poorly — because the higher the pH climbs, the smaller the share of your free chlorine that exists in its effective form.

Lo 'N Slo brings pH back down, and reduces total alkalinity along with it. It dissolves quickly, works in every pool type and on every surface, and swimmers can return 15 minutes after application. Dosing is organized by how high your pH actually reads, so the correction is sized to the problem rather than applied as a single generic scoop.