Fluval U4 Poly-Max

Poly-Max Cartridge for U4 Underwater Filter, 2-Pack
 
Specifically designed for the Fluval U4 filter, the U4 Poly-Max Cartridge helps control green water and unsightly algae growth by trapping and adsorbing phosphate, nitrite and nitrate.
 
Features
 
Chemical filter media
Produces crystal clear water, reduces odor, and creates ideal conditions for fish and plants
Helps reduce overall aquarium maintenance
Suitable for freshwater, saltwater or reptile environments
Convenient 2-pack format
2 x poly/clearmax filter cartridge included