Juwel Carbax Bioflow is a premium hard coal-based granular activated carbon filter media specially formulated as an optional upgrade for the Juwel Bioflow internal filter system. Unlike conventional activated carbon media, Carbax activates the entire carbon grain rather than just the surface, delivering superior and long-lasting absorption of discolouration, odours, toxic substances, and medication residues to ensure crystal-clear aquarium water. Designed to fit neatly into the Bioflow filter basket, Carbax is easy to install and replace, and is recommended for use whenever water quality issues such as discolouration or odour are detected. Available in Medium (Bioflow 3), Large (Bioflow 6), and XLarge (Bioflow 8) sizes to suit the full range of Juwel Bioflow filter systems. Replace every two months for optimal performance.