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Pool Filter Cartridges - When To Clean It? When To Replace It?

Using cartridge pool filters are a great option for swimming pools because they are easy to maintain and simple to clean. Properly maintaining your cartridge filter often comes down to whether to clean the cartridge or replace it.

Check out these expert tips to help you know when each option is appropriate.

When To Clean Your Filter Cartridges

The simple answer? When the pressure on your gauge reaches 8-10 psi above the standard starting pressure, you should clean the filter.

For example, if you bought brand new filter cartridges, and the first time you started the system the psi was 10, then you would need to clean that filter when the pressure reached around 18 psi. Other times you should clean your filter include:

  • During an algae bloom treatment
  • After major storms
  • As part of opening or closing your pool

We have more information in this step-by-step guide on how to clean a cartridge pool filter.

When To Replace Your Filter Cartridges

Pool filter cartridges have no expiration date, so it’s important to know signs of a cartridge that needs replacement.

Let’s start with the bands. Contrary to what you may have heard, those bands are not wear bands. This means that the cartridge does not need to be replaced at the first sign of a broken band. However, the bands will break down over time. If you see a significant amount of breakage on the bands, look closely at the cartridge to ensure it is still in good condition. Those bands are specifically designed to ensure proper spacing between the pleats of the filter, so if the bands do break, your filtering ability will be diminished.

Next, look at the coloration of the cartridge. It will never be as white as when you first installed it, but it should not have permanent dark brown or oily stains. If it does, that means it is saturated with oils. You need to soak it in a cartridge cleaner to help pull those oils out. If you can't remove the oils with a cartridge cleaner solution, you may need to replace the cartridge.

PRO TIP: It is not a good idea to use any sort of acid dilution on a filter cartridge.

Now, look between the pleats. You don’t need to check them all, but check enough of them to get a good understanding of whether or not the material is starting to fray or come apart. If the material is visibly degrading, you should replace the cartridge immediately because you are no longer getting proper filtration.

The final sign that you need to replace the filter cartridge - the end caps are broken. Small stress cracks may not be a problem, but any actual breaks in the cap are a strong indicator that the pool filter cartridge needs to be replaced.

For more information on pool filter cartridges or any other aspect of pool care, call or visit your local Leslie's.

Recommended Products

Leslie's Cartridge Cleaner

Cartridge Cleaner

Filter cleaner tool

Cleaner Nozzle

pool filter cartridge

Filter Cartridge

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Leslie’s makes every effort to provide accurate recommendations based upon current ANSI/APSP/ICC-5 2011 (R2022) standards, but codes and regulations change, and Leslie’s assumes no liability for any omissions or errors in this article or the outcome of any project. You must always exercise reasonable caution, carefully read the label on all products, follow all product directions, follow any current codes and regulations that may apply, and consult with a licensed professional if in doubt about any procedures. Leslie’s assumes no legal responsibility for your reliance or interpretation of the data contained herein, and makes no representations or warranties of any kind concerning the quality, safety, or suitability of the information, whether express or implied, including, without limitation, any implied warranties of merchantability or fitness for a particular purpose.