The application of Al⁺Clear^® products in the presence of available moisture lowers the litter and / or the pad surface pH through hydrolysis (reaction with moisture) of the aluminum sulfate, the primary chemical component in all Al⁺Clear^® products.  Each hydrolysis reaction generates hydrogen ions (H⁺), also referred to as acid ions, which lower the pH of the litter or pad.  Al⁺Clear^® A7 also contributes additional pH reduction from the additional sulfuric acid in the formula.  Formulated for drier litter and pad conditions, Al⁺Clear^® A7 requires less moisture for activation than Al⁺Clear^® Poultry Grade Alum.