Tropical Marine Gravel is carefully graded to obtain a good grain size and colour. It has a highly porous structure which makes it an ideal biological filter medium, especially when used in conjunction with mechanical filtration.
It should be noted the Tropical Marine Gravel has equal buffering capacities to calcium or Dolomite gravel, but its larger surface area makes it the ideal choice where a buffering and biological substrate is required.
Tropical Marine Gravel will not compact like Dolomite or calcium gravel under normal working conditions. Therefore, with its buffering abilities, it is ideal for the marine aquarium and the special freshwater aquaria where higher pH levels are required.
Because the gravel is in different shapes the gravel size varies slightly with the coarse around 10mm, the medium around 6mm and the fine around 4mm.