Fluval Polycarbon cartridges features two sides for effective chemical filtration the crucial second stage in the filtration process The polyester filter pad side filters out fine debris and contaminants The carbon side filters out harmful liquid substances colorants and odors The Fluval Polycarbon cartridge works in part with the Fluval Filter Foam Pad to help keep your aquarium healthy and clean

Provides effective chemical filtration custom fit for the Fluval U3 Filter Traps fine debris improves water clarity and removes impurities Easy to replace Works in freshwater marine or reptile environments