Anthracite performance as a media filterTransporting droughts in external voids.Unlike active carbon that absorbs dirt in internal voids, anthracite holds dirt in the outer cavities between particles. It is more common to remove the sand than the silica sand, so it has larger outer cavities that can lift up much of the dirt. Filters from top to bottom Anthracite can filter from top to bottom the filter layer Easy to clean (back wash)