Freshwater Zym Bac contains species of bacteria that are beneficial when starting or acceleration the nitrogen cycle of biological filtration, particularly in those aquariums in which the proper bacteria are in short supply or are not naturally present. Freshwater Zym Bac will greatly bolster the number of naturally occurring nitrifying bacteria present, resulting in shorter cycle times and more efficient biological filtration. Freshwater Zym Bac will help replace bacteria lost due to medicating, changing filter media, adding new livestock, etc. The bacteria provided in Freshwater Zym Bac are particularly effective, hard and beneficial over the long term in aquarium keeping. The better water conditions provided by these bacteria will improve health and longevity of fishes and other aquatic life in aquariums.