These specialist filter cartridges from Fluval are designed to fit directly into the Fluval U Series filters, and help to add an extra layer of filtration within your aquarium, be it Freshwater or Marine.
It combines two unique sides, one of carbon to bring effective chemical filtration and the other of polyester to add an extra fine layer to remove even smaller particles. They come with 2 in each pack, and should be replaced every 2 - 4 weeks, to ensure they are kept at their most effective. They can be changed sooner if there is a noticable reduction in flow, such as after a big move around within the tank, resulting in a lot of particles, as the polyester pad will clog up sooner.
The Poly / Carbon Cartridges have been designed to trap fine debris and to help remove odours, resulting in improved water clarity in your aquarium. To work out the right cartridge for your filter, simply match the U Series number. You may need to replace your Fluval U Series Filter Foams and Biomax media as well, to ensure the best filtration.