Filtralite is an expanded clay product with high porosity. The pores are of varying sizes from small micro pores to larger pores (1-2 mm), most of them linked in labyrinthlike structure. By crushing the expanded clay beads, their large surface area is exposed. The large porous surface makes the Filtralite aggregates perfect for different types of water treatment. Porosity and density are controlled during manufacture of Filtralite. Dry particle densities can be produced in the range of 500-1600 kg/m³, with a corresponding dry bulk density of 300-900 kg/m³.

During the burning of the clay, strong bonds are created. Consequently the beads are unnaffected by any traditional gases or liquids, and release of harmful substances is avoided. Resistance to chemical breakdown is very high, and the acid loss is minimal.

Despite its low density and high porosity Filtralite has a high abrasion and impact resistance. Material strength is dependent on particle density. When particle density is increased, resistance to abrasion and physical impacts is increased.