Juwel BioCarb Sponge Bioflow is a high-quality carbon sponge filter media designed for use in the Juwel Bioflow internal filter system, providing effective chemical filtration by absorbing odour compounds, turbidity, and toxic substances from aquarium water to maintain clean, clear, and healthy conditions. Acting as the chemical filtration stage within the Bioflow system, the BioCarb Sponge works alongside the poly pad and biological filter media to deliver comprehensive multi-stage filtration performance. Supplied in a convenient pack of two, the BioCarb Sponge is easy to remove and replace and should be changed approximately every month to ensure continued chemical filtration efficiency. Available in Medium (Bioflow 3), Large (Bioflow 6), and XLarge (Bioflow 8) sizes to suit the full range of Juwel Bioflow filter systems.