Fluval U Series Poly-Carb Cartridges are genuine replacement chemical and fine mechanical filter media designed specifically for Fluval U3 and U4 Underwater Filters. Each cartridge combines two filtration surfaces to help polish aquarium water, capture fine debris, and remove dissolved impurities, odours and discolouration.
Available in separate U3 and U4 sizes, each pack contains 2 replacement cartridges shaped to fit the correct Fluval U Series filter.
Available Sizes
✔ U3 Poly-Carb Cartridge – 2 Pack – Fits Fluval U3 Underwater Filter
✔ U4 Poly-Carb Cartridge – 2 Pack – Fits Fluval U4 Underwater Filter
Key Features
✔ Genuine Fluval replacement filter media
✔ Dual-sided filtration cartridge
✔ Polyester side captures fine debris and suspended contaminants
✔ Activated carbon side helps remove dissolved impurities
✔ Helps reduce unwanted aquarium odours
✔ Helps remove water discolouration and colourants
✔ Supports clearer, cleaner-looking aquarium water
✔ Pre-shaped for easy installation into the correct U Series filter
✔ Convenient 2 pack
✔ Suitable for freshwater and saltwater aquariums
Perfect For
✔ Fluval U3 Underwater Filters
✔ Fluval U4 Underwater Filters
✔ Routine filter media replacement
✔ Improving aquarium water clarity
✔ Removing fine suspended debris
✔ Reducing odours and discolouration
✔ Maintaining effective chemical filtration
Please Note
The U3 and U4 cartridges are different sizes, so select the cartridge that matches your specific Fluval Underwater Filter.
