Red Sea Reefer Filter Media Cup - 4" Durable Aquarium Filter Sock Replacement - Easy Maintenance for Saltwater & Reef Tanks;

Red Sea Reefer Media Cups can be used in place of standard filter socks and be filled with a variety of filter materials. The design of the cup allows it to be dropped into the sock holder and can used with a wide variety of media, including: filter pads, filter floss, biological media, carbon, and GFO. The Filter Media Cup from Red Sea is an alternative to the 4"/10cm micron filter bag. This cup is compatible for all Red Sea REEFER and MAX systems and is easy to clean. The media cup holds 1 liter of filter media with optimal water flow and comes with a free media bag.