Fluval C3 Filter Media Bundle: Carbon 3-pk, Ammonia Remover 3-pk, Foam Pad 3-pk Contains a carbon 3-pack, ammonia remover 3-pack, and a foam insert 3-pack Ideal for new or heavily populated freshwater aquariums and helps to reduce stress on fish Poly/Foam Pad effectively performs the first and second stages of mechanical filtration by first capturing the large particles and then the finer debris The Activated Carbon provides superior adsorption qualities that effectively eliminate odours, discolouration and impurities The Ammonia Remover then removes and controls harmful ammonia and nitrite, which reduces stress on fish as a result