Cirax is a biological filter medium that offers beneficial bacteria optimal conditions for colonization due to its highly porous structure and large surface area. Juwel Cirax is a highly porous granulate based on ceramics, which provides an ideal environment for beneficial filter bacteria thanks to its extremely large surface area. In your Juwel filter, Cirax thus contributes to excellent water quality. The use of a special basket tailored to the size of your Juwel filter allows for easy handling, while the optimized filling volume enables a long lifespan of up to one year.