ATM Aquarium Products Colony Nitrifying Bacteria Freshwater for Aquarium CYCLES: The one that works, effectively imports actual true nitrifying bacteria AUTHENTIC: Other products don't contain the right species of bacteria, Colony Freshwater does! STRAINS: Nitrosomonas & Nitrobacter for primary ammonia and nitrite consumption in the freshwater environment INSTANT: Add fish same day, not weeks later PROVEN: Used and approved by commercial aquariums