TMC Gravel Fine – 3mm has carefully been graded to obtain a uniform grain size and colour. It features a highly porous structure which makes it in ideal biological filter medium, primarily when used in conjuction with mechanical filtration.
TMC Gravel Medium has a large surface area which makes it perfect where a buffering and biological substrate is required. Therefore it's ideal for any marine aquarium and for freshwater aquaria where higher pH level is required.
Ideal as both a mechanical and a high surface area biological filter media