Powerful, convenient, and effective, Thetford's Aqua-Kem Liquid is the #1 selling holding tank deodorant of all time because it does the job better than any other product! Aqua-Kem liquefies waste fast and breaks down tissue to prevent clogging. Its powerful detergents clean tank walls and drain lines. This 100% biodegradable liquid works around the clock in all weather conditions, and is environmentally safe when disposed of properly. 8 oz./40-gal. tank. Contains formaldehyde. 1 gallon.