Biological Media: Balance and Detoxification Drs. Foster & Smith
Educational Staff  Introduction to biological filtration
Biological media is any inert material that houses the
beneficial bacteria colonies that break down ammonia to a less
toxic form. Biological media is normally placed in your
filtration system where water is forced through, bringing
nutrients and oxygen required by the bacteria to complete the
nitrogen cycle.  A variety of media is available for bacteria
cultivation. Small biological media, such as Cobalt Aquatics
Ceramic Rings, Azoo Bio-Glass, or Eheim Ehfisubstrat are an
excellent option if you have a small aquarium. They are
extremely porous and boast incredible surface areas. Plastic
media, such as BioMate or Coralife Bio-Balls do not have the
extensive surface area, but they are unlikely to clog and never
need replacing. Bio balls also work to degas ammonia before
bacteria break it down, lessening the load on the filter.  When
starting a new aquarium, a great source of bacteria is a s