Purigen is a GREAT media I run it in all my systems. However the design of a phosban reactor is better suited for media with a larger partial size. If you want to remove organtics a good option for that type of reactor would be Pura Complete. Not only will it remove your organtics but also phosphates aw well as other elements. If you do put Purigen in the reactor be sure to put it in a media bag for fine partial size