Cerapore (Ceramic filter media for Biofilter). It is produced from pure ceramic fired at high temperature and is free of residues so it can be safely used in fresh and salt water aquaria. Cerapore has an enormous internal surface area that is fully available for bacterial colonization, and its open pores are so formed that the media is non-clogging and stays clear, even under long term use. This results in high biological waste reduction rates in a very small volume. Cerapore may be used in trickle filters or in submerged filters. When used submersed, anaerobic areas may be formed in the center of the media, which may help with nitrate reduction. Under ideal conditions, 1 liter of Cerapore will filter 200 liters of fresh or saltwater aerobically.