Juwel Nitrax Removal Sponge is a specialised biological filter media designed for use in the Juwel Bioflow internal filter system, containing specialist micro-organisms that actively break down toxic ammonia and nitrite while also anaerobically reducing nitrate levels in freshwater aquariums. By lowering nitrate levels, Nitrax helps suppress unwanted algae growth and supports the overall vitality and health of fish, plants, and beneficial bacteria. A key component of the Juwel Bioflow multi-stage filtration system, the Nitrax Removal Sponge is easy to install and replace and should be changed approximately every two months for optimal biological filtration performance. Available in Medium, Large, and XLarge sizes to suit the full range of Juwel Bioflow filter systems.