Bio Rio G is a sintered glass filter media suitable for biological filtration. It is porous with a large surface area.  Many filtration microorganisms settle and demonstrate high filtration performance. The pieces are irregular. The irregular shapes of the filter material allow gaps to be formed when filled in the filter.  This feature reduces clogging and allows high contact of water and media.  It is made of inert material and does not impact water conditions such as pH and hardness.  As a result, long-term stable filtration can be achieved.