API Bio-Chem Stars Pouch, 20 countAPI BIO CHEM STARS biological media provides a home for growing massive colonies of nitrifying bacteria to establish and maintain a healthy aquatic ecosystem. The nitrifying bacteria convert harmful ammonia into nitrate. This is called the nitrogen cycle, and it occurs naturally in all underwater environments. Your fish will produce waste, which fuels the growth of the beneficial bacteria that will comprise your biological filter. These bacteria