Cirax is a biological filter medium which creates the perfect colonisation conditions for useful bacteria, due to its large, highly porous surface.
 
In your JUWEL filter, Cirax helps to ensure excellent water quality due to effective biological cleaning.
 
Cirex M (Compact) - 9.5 x 9.5 x 4.5 cm
Cirex L (Standard) - 12 x 12 x 5 cm
Cirex XL (Jumbo) - 14 x 14 x 5 cm