Keep your black tank fresh and clean with Camco's TST MAX Citrus Toilet Treatment. This product is specially designed to eliminate odors, break down waste, and ensure top performance in RV and marine tanks. TST Max liquid treatment is designed to be safe for your septic tank and the environment. The ultra-concentrated formula offers a sustainable solution for your toilet treatment needs. With just a 2-ounce application, you can keep up to a 40-gallon tank smelling fresh for seven days.