Instant Liquid Acid, you no longer have to worry about muriatic acid spilling in your car, on your clothes, or storing the hazardous liquid in your garage or shed! In The Swim's dry powdered acid, Instant Liquid Acid has no harsh chemical odors and is . You simply add Instant Liquid Acid into your pool like you always have! Safer and easier to use than muriatic acid as a pH decreaser in pools and spas.