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.
- 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