OMNI® 23820OMN 1 qt Bottle Filter Cartridge Cleaner. Particles (dirt, dead algae, greases, oils etc.) captured in the filter pleats build up over time and the filter works less efficiently. The build-up of debris makes it more difficult for the water to pass through the filter element. Chemical cleaning is absolutely essential in order to maximize the life and efficiency of the cartridge filter. For best results and longer filter life, rinse the chemically cleaned filter thoroughly and allow it to dry before returning it to service.