BLUFIBREBlufibre is a synthetic fibre, neutral and non toxic, which ensures an effective mechanical water filtering action, captures impurities for water always clear. Perfect for internal and external filters, for all fresh and salt water aquariums. Ideal as mechanical pre filter (first stage of the filter), as final filtering material (last stage, before water return), as biological filtering (if not rinsed frequently). Package of 100 g. net.