Activated Carbon Board - Contains 3 layers of materials; filter sponge, active carbon and bio sponge to ensure the best filtration.

FILTER SPONGE - Mechanical filter material that absorbs suspended substances and purifies the water.

ACTIVE CARBON - Chemical filter material that eliminates colour and smell increasing clarity of water.

BIO SPONGE - Biological filter material that grows aenerobic nitrifying bacteria to remove poisonous compounds.

Features 4 separate sponges.