Cartridge Filter not Filtering


New member
Sep 10, 2021
Southern Ontario
Greetings - I am in the midst of rebooting the pool after a year of no use due to plumbing leaks. Leaks are repaired and I am faced with a pond coloured pool. Have been hitting it with chemicals and started the long process of vacuuming when the problem of dirty water coming right back through the returns when I vacuum. Cartridges are three years old although they had scant use last year. My hunch was to replace the cartridges and commenced vacuuming again. after about ten minutes the stream of 'unfiltered' water is coming through the returns again. I can see no evidence of problems anywhere else. The water coming through the returns 'appears' ok when I'm not vacuuming although it is hard to tell. The pool bottom is covering in dirt, leaves etc and visibility is at best two feet. If there is a problem elsewhere (in the filter) how do I check or test for that? Have I overpowered the new cartridges? Am I expecting too much from the filter? Anyone with similar experiences and solutions or suggestions? Thank you


Gold Supporter
LifeTime Supporter
TFP Guide
Oct 25, 2015
Palm City/FL
Pool Size
Salt Water Generator
SWG Type
CircuPool RJ-30 Plus

Welcome aboard! Please read thisABCs of Pool Water Chemistry asap and ask any questions you may have.Very likely it's just plugged and needs to be cleaned. For most filters you can clean them many times before replacing but you could well have ruptured a filter. What's the pressure? And as Mark indicated a photo of your pool and filter cartridges would help a lot. With a pool in the condition you describe I'd manually remove as much debris as possible. The more you leave in the more it will chew up chlorine needlessly. Then test the water using a recommended test kitTest Kits Compared. If you want to use TFP methods you'll need a test kit. You will need to SLAM most likely but will need to test your water first in case a water exchange is needed. No need to treat and then dump chemicals down the drain.

It would also help a lot if you could provide a signature. We are 100 % volunteer and this helps our volunteers be more effective with their time. Here's how to do it. We also don't sell anything so you can always trust our advice is not conflicted.

I hope this is helpful.

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