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

Compatibility: 

• U4 Underwater Filter

Item #: A483