Marc Weiss' Bacter Vital is the modern solution to fully cycle a new aquarium and to energize and recycle established aquariums. Ideal for under gravel filters, natural, planted systems and biological filters. Contains all natural biological catalysts and nearly 600 species of microorganisms. Properly cycles the aquariums by synchronizing the sulfur, phosphorous, and carbon cycles with the nitrogen cycle as per modern scientific findings. Neutralizes ammonia, nitrites and binds heavy metals. Can be used with ammonium chloride. One ounce cycles 100 gallons. Also available in Marine Formula.