I don't know anything about a cartridge filter but with my sand filter I have a multi-port valve that can divert the water from the pump to several different locations (filter, waste, backwash, rinse). When I get something in my pool that the filter won't "catch" I'll vacuum to waste and this gets rid of it.

Apparently you don't have this option available. I'm not sure what to tell you, maybe someone else will chime in and help out.