SafeStart accelerates the establishment of the bio-filter in newly set-up freshwater aquariums. The live bacteria start working immediately to provide a safe and healthy environment for your fish withouth the long wait. SafeStart can also be used after a water change, when adding fish or after medicating. Features & Benefits: Live nitrifying bacteria start working immediately to reduce dangerous ammonia and nitrite. SafeStart prevents new tank syndrome for healthy fish. the patented mix of Nitrosomonas, Nitrosospira & Nitrospira is proven to work. Shelf-stable formula requres no refrigeration for added convenience. Treats 15 gallons.