Filter Media Cartridge Fluval BioMax for U2 (A15207) – Biological filtration media

Fluval BioMax filter media cartridge for U2 (A15207) is a biological filtration insert designed to support the growth of beneficial nitrifying bacteria in aquarium systems. The cartridge contains a porous, ceramic-like structure that increases surface area within the filter chamber to improve ammonia and nitrite conversion while fitting directly into Fluval U2 filter units. It is intended as a replacement media for the biological stage of combined mechanical-biological filtration and is suitable for freshwater aquariums and compatible setups that require effective biological support.

Advantages

This BioMax cartridge offers a large internal surface area in a compact form factor, promoting stable populations of nitrifying bacteria responsible for converting toxic ammonia and nitrite into less harmful nitrate. The porous ceramic-like composition provides durable, long-lasting media that does not compact easily, maintaining water flow and biological efficiency. Its shape and size match the Fluval U2 filter compartment for straightforward replacement without modification.

Suitable for

• Freshwater community aquariums using Fluval U2 filter units
• Fish-only and planted tanks requiring biological filtration support
• Routine media replacement to maintain nitrifying bacteria colonies

Key specifications

• Porous ceramic-like media structure for high surface area
• Designed to fit Fluval U2 filter cartridge compartment
• Intended for biological stage within mechanical-biological filtration
• Suitable for freshwater aquarium systems
• Compact cartridge shape for easy insertion and removal

How to use

Remove the used cartridge from the Fluval U2 filter according to the filter manufacturer's maintenance instructions. Rinse the new BioMax cartridge briefly in dechlorinated water to remove any dust from packaging, then insert it into the biological media slot of the filter so it sits securely in place. Reassemble the filter and restart circulation. Replace the cartridge on a schedule that maintains effective biological filtration; do not replace all biological media simultaneously if preserving established bacterial colonies is desired.

Usage recommendations

For stable biological filtration, stagger replacement so established bacteria remain in the system: replace one cartridge at a time and monitor water parameters after replacement. Use only in freshwater setups compatible with Fluval U2 filter units and follow routine filter maintenance to prevent mechanical clogging that can reduce biological efficiency.