Tetra SafeStart Plus 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 without the long wait. SafeStart Plus can also be used after a water change, when adding new fish, or after medicating. Prevents "new tank syndrome". A patented mix of Nitrosomonas, Nitrosospira, and Nitrospira proven to work! Requires no refrigeration for added convenience.