Cartridge filter questions


Jul 12, 2019
Recently bought a house with a pool that has a Sta-Rite System 3 cartridge filter and trying to learn the ropes. My cartridge filter gets very dirty quickly and I have had to clean it recently after each vaccuming. There is a large tree that sheds a lot in the pool so this is contributing to the problem. I also have been dealing with a little algae problem the past two weeks after returning from a vacation (I am awaiting my new test kit to arrive in the mail so I can begin the SLAM process).

1) How do you know when you need to replace the cartridges?

The cartridges themselves look a little worn. I have no idea when the previous homeowners last replaced them.

2) Are there advantages to switching from a cartridge filter to a sand filter or a SWG?


Well-known member
Apr 2, 2016
Hillbillyville, MO
I don’t know your filter but I have one large one. I use hair nets in the skimmer basket and it helps tremendously. I change them once a day. Very cheap compared to filters.

The swg produces chlorine so the pool is easier to maintain. I love mine.
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Gold Supporter
Mar 21, 2016
Marrietta Ga
Yes get skimmer nets like Tom suggested. I just started using them this year after being here 12 years and it helps.
Also how are you cleaning your filter? Need a strong spray to get it clean betweem the fins. I have a low pressure electric pressure washer that has a wide spray and use it about every 2nd cleaning
Maybe order a new one but wait for your SLAM to finish so you will have a clean filter and water to start
For nets order hair nets off amazon, get like a 100 for $12


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

There is nothing wrong with your filter. It is doing what you pay it to do... Filter out all the "stuff" in the water. Algae can clog a filter in just a day or two..

You should never vacuum directing into any filter.. You should vacuum to waste (which you can't do) or you should have some type of inline bag/filter..

You can always add a three way valve between the pump and the filter that will allow you to vacuum to waste.

My cartridges are 5 years old and I expect them to last for at least 5 more years.

I believe your major issue is the algae. Once you get that taken care of your filtering problems will go away.


Jim R.


Jul 12, 2019
Thanks for the quick replies. I am just using a hose with a spray nozzle attached to clean filter.

Is there anything I should be doing for the algae problem between now and the time my new testing kit arrives (Thursday)? I know I can't really begin SLAMming it until I have proper test results.

I have some granular shock left. I know its not recommended but is it OK to use until I begin the SLAM.


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
Add 5 ppm FC worth of liquid chlorine each evening until your test kit arrives.

Not much else. If the filters are plugging too quickly, remove them. You will just recirculate the water until you can get the SLAM process started.
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