Premium research grade low ash fluval carbon is highly porous providing large amounts of surface area for adsorbtion of impuritiesr it effectively removes heavy metals odors discolorations organic contaminants and pollutants to leave your aquarium water crystal clear and sparklingr fluval carbon does not raise phosphate levelsr for use in freshwater and marine environmentsr one pack contains 3 x 100g nylon bags of activated carbonr for filter models 106 206 306 406 fx5 105 205 30