Cartridge filters are service items. Cleaning removes trapped debris, but eventually the filter media and structure wear to the point that cleaning no longer restores normal performance.
Signs replacement may be due
Watch for torn or frayed pleats, cracked end caps, collapsed media, bands that no longer hold the pleats correctly, or a cartridge that remains heavily discolored and restricted after proper cleaning.
Performance matters more than age alone
Two identical cartridges can have very different service lives depending on pump operation, debris load, water chemistry and cleaning practices. If pressure rises unusually quickly after cleaning or water clarity is becoming harder to maintain, inspect the cartridge closely.
Use the correct replacement
Filter cartridges are not interchangeable simply because they look similar. Match the replacement to the filter manufacturer and model specifications.
Nexus is building the Replacement Parts catalog around exactly this type of model-specific maintenance need.