Penn-Plax Cascade 300 Aquarium Filter Cartridges, 3-Pack with Carbon & Floss

Penn-Plax Cascade 300 GPH replacement filter cartridges are aquarium media made to filter water in Cascade 300 GPH hang-on filters, with activated carbon and poly-fiber floss in a 3-pack.

• Activated carbon helps clear discoloration and odors while trapping pollutants — for clearer, fresher-smelling aquarium water.
• Poly-fiber floss screens particulate matter and debris — adding a physical filtration layer.
• Made for freshwater and marine aquariums — usable in either type of aquatic environment.
• Typically lasts 6 to 12 weeks, depending on tank conditions — helping you plan routine media changes.
• Preassembled, slide-in cartridges — designed for quick replacement in the filter compartment.

Aquarium water can collect visible debris, odors, and other unwanted substances as a tank runs. These replacement cartridges combine a carbon layer with a poly-fiber barrier to address different kinds of water contaminants in one filter insert. They are made for routine upkeep of a compatible hang-on power filter, whether your aquarium is freshwater or marine.

What do the carbon and floss layers filter?

The activated carbon is designed to trap pollutants in its pores and help remove discoloration, odors, ammonia, nitrites, and other harmful toxins from aquarium water. The poly-fiber floss screens out particulate matter and debris, providing a separate physical barrier. Together, the two materials handle both unwanted substances and suspended particles. The dual-action media is designed to make a marked difference in water quality within 24 hours.

• Carbon supports water clarity by addressing discoloration and odors.
• Carbon pores trap pollutants instead of allowing them to enter the water.
• Poly-fiber floss screens debris and particles from the water passing through the filter.

Which filter does this replacement media fit?

These cartridges are sized for the Penn-Plax Cascade 300 GPH hang-on filter, model CPF5. Each measures approximately 10 x 3 x 7 inches (25.4 x 7.62 x 17.78 cm) and fits the Cascade 300 filter tray. The close fit is designed to leave no gaps where debris and contaminants could bypass the cartridge and return to the aquarium. For the intended fit, match your filter to the Cascade 300 model CPF5.

• Filter type: Cascade 300 GPH hang-on power filter.
• Model compatibility: Cascade 300, model CPF5.
• Cartridge dimensions: approximately 10 x 3 x 7 inches (25.4 x 7.62 x 17.78 cm).

How often do I replace the cartridges?

Each cartridge typically lasts 6 to 12 weeks under normal conditions, with tank conditions affecting its useful life. The preassembled insert slides into the filter compartment, so replacing the media does not require assembling the cartridge. When used with the Cascade 300 GPH CPF5 filter, the cartridges are intended to help protect aquarium water from pollutants.

• Supplied as three replacement cartridges for successive filter changes.
• Preassembled format slides into the filter compartment.
• Typical service life: 6 to 12 weeks, depending on conditions in the tank.

Can I use these cartridges in freshwater and marine tanks?

Yes. The cartridges are suitable for both freshwater and marine aquarium environments. Their carbon and floss media provide filtration for discoloration, odors, pollutants, and particulate matter in either setting. Penn-Plax also brings over 60 years of innovation in pet products to this replacement media.

• Intended for freshwater aquariums.
• Also suitable for marine aquariums.
• Designed to work with the Cascade 300 GPH CPF5 filter as part of its filtration setup.

This three-cartridge set suits aquarium keepers maintaining a Cascade 300 GPH hang-on filter in a freshwater or marine tank and looking for replacement media with both carbon and particle-screening layers. Its fit is specific to the Cascade 300 model CPF5, with cartridge dimensions of approximately 10 x 3 x 7 inches (25.4 x 7.62 x 17.78 cm).