Dry acid vs muriatic acid: Dry acid wins for speed and safety

Sodium bisulfate (dry acid) drops pH fastest with no mixing or fumes—just sprinkle it in. Muriatic acid works but requires gloves, goggles, and careful pouring. For a 10,000-gallon pool at pH 8.0, use about 1.5 pounds of dry acid to hit 7.4.