Keep your multi-stage mechanical filtration operating effectively with Fluval C3 Foam Pad Filter Media. Good water quality is essential in keeping your fish healthy and large debris particles can cause toxic ammonia levels and cloudiness. Fluval C3 Foam Pad Filter Media works in the Stage 1 mechanical filter process and captures large debris， making chemical and biological filtration more efficient. The porous pad is replacement media for the Fluval C3 Series multi-stage filter. The result is better water quality and cleaner， clearer water.