Fritz Pro Aquatics Ammonium Chloride - Ammonia Source for Fishless Cycling (500 g)Brand: Fritz Aquatics Features: Essential for Nitrifying Bacteria: Provides a precise ammonia source required for beneficial bacteria such as FritzZyme or TurboStart to thrive and complete the nitrogen cycle when fish are not present Only dose in systems with no livestock, for fishless cycling only Highly Concentrated Formula: Economical and efficient just 4. 5 g per 100 gallons produces approximately 4 ppm of ammonia. A little goes a long way