In most aquariums, the biological cycle is started by introducing fish into the aquarium. The fish excrete ammonia which acts as a food source for nitrifying bacteria. Nitrifying bacteria convert ammonia into nitrite and then nitrite into nitrate. Fritz Ammonium Chloride (NH4Cl) can be used as a source of ammonia to initiate the growth of nitrifying bacteria without the presence of animal life. Fish should not be present while using ammonium chloride.
Aquarium ammonia concentration should be raised to 3- 4 ppm before adding a source of nitrifying bacteria such as FritzZyme or FritzZyme TurboStart. Be careful not to use too much ammonium chloride. One level teaspoon of ammonium chloride is approximately 4.5 grams, 4.5 grams per 100 gallons of aquarium water will create an ammonia concentration of approximately 4 ppm. Continue to monitor both ammonia and nitrite levels. Do not reapply ammonium chloride or add fish until both ammonia and nitrite levels are at or near zero concentration. Once ammonia and nitrite concentrations are at zero, you should either add a second dosage of ammonium chloride or add fish so as not to interupt the food source of your biological filter for more then 72 hours (3 days).