It would be great if you could put your basic pool specs/equipment list in your signature. That makes it simpler for us to answer your questions.
I believe you have a cartridge filter. The two things that tend to go wrong are that the filter cartridge doesn't always seat down into the filter correctly, allowing water to go around the filter. Or, there can be a tear in the filter fabric, which requires replacing the cartridge.
I believe you have a cartridge filter. The two things that tend to go wrong are that the filter cartridge doesn't always seat down into the filter correctly, allowing water to go around the filter. Or, there can be a tear in the filter fabric, which requires replacing the cartridge.