Filtration & Circulation /
How Often Should You Replace a Pool Cartridge Filter?
A pool cartridge filter usually needs cleaning more often than replacement. Replace it only when it’s damaged, collapsed, or still performs poorly after proper cleaning.
Archive date: this article was written for PoolSkimmer on Oct 24, 2026 and given the earlier archive date of Nov 2, 2025 so the blog reads as an organized archive. It was not published on that date.
Pool cartridge filter: when to put in a new one
There is no set timetable for replacing a pool cartridge filter. For the majority of pools, it is more useful to ask if the cartridge is still doing an adequate job of cleaning than to follow a rigid schedule. The rule of thumb is to give the filter regular maintenance and swap out the cartridge once you see signs of damage or that performance has slipped. When in doubt on the timing, the manufacturer’s manual is your best reference.
Indications that the filter needs to go
Before a cartridge fails completely there are usually some obvious tell-tale signs. You might notice:
- Any tears, broken seams or fraying at the edges
- Pleats that will not clear of dirt even after a good cleaning
- Media that has become brittle, warped or has collapsed
- A pressure gauge that refuses to come down to normal levels
- Poor water flow that persists after you have done a proper clean and reinstalled the unit
Should the cartridge appear fine but the pool water remains cloudy or circulation is lackluster, look for the cause elsewhere in the system.
To clean or to replace?
Follow this straightforward process to make your decision:
1. Shut off the pump prior to working on the skimmer or filter. 2. Refer to the equipment manual to open the housing. 3. Examine the cartridge for clogging, collapse or any other damage. 4. Clean in accordance with the maker’s directions. 5. Put the cartridge back in place, ensuring the O-ring, lid and housing are all secure. 6. Fire up the pump and observe the flow and pressure.
If the filter does not respond to a correct cleaning and the pressure is still high, the cartridge has likely run its course.
Making a habit of inspection
During the height of swim season it is wise to get into the habit of a weekly check, particularly with a pool that sees a lot of traffic and debris. This is not to say you should be changing it every week, but rather to stay on top of clogs so as not to put undue strain on the pump and filter.
More frequent inspections are in order if:
- The skimmer basket is filling up with haste
- There is an accumulation of leaves or dust in the area
- You find yourself vacuuming the pool often
- The pressure gauge is climbing quicker than normal
- The pool is in constant use
Why some owners replace prematurely
It is easy to make errors that lead to an early replacement. Some will put in a new cartridge without first ruling out a simple clog, or they may not reinstall it properly. Others might assume any uptick in pressure is a sign of failure, or they will overlook a dirty skimmer basket and other restrictions on flow. A blocked hose or a circulation issue can be mistaken for a worn-out cartridge; check the simple things first.
Some also tend to use cleaning techniques that are not sanctioned by the manual.
Time to bring in a pro
A qualified pool professional should be contacted under certain circumstances:
- If the filter housing is cracked, difficult to seal or is leaking
- Pressure and flow issues remain despite your efforts
- There is reason to believe the pump or plumbing is at fault
- You are unsure of the fit or cannot get the housing to close
Safety is paramount. Do not enter the water if the equipment is acting up electrically or conditions are unsafe. Heed the chemical labels and the equipment manual, and wear the appropriate PPE. Before you access the skimmer basket, the pump must be off; never put your hands into operating suction equipment.
Sources and further reading
- [Hayward: Weekly pool maintenance](https://www.hayward.com/maintenance/weekly-pool-maintenance)