How To Clean a Pool Cartridge Filter


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The purpose of a pool cartridge filter is to clean your pool water by capturing debris and decontaminates in the folds of the filter. With time these folds will become clogged, water will not flow thru the filter as easily, and pressure within the filter will increase. Operationally, with water flow down, you will not be turning you pool water as frequently and your pool decontaminates will start to build up. It's time to clean your filter. As a general rule of thumb, your filter should be clean at least once a month during the summer and every other month if your pool is operational during the winter. Although this description is specific to a Hayward cartridge filter, many of the steps can apply to other models of cartridge filters.

Please click here to view pool filter cartridges.  

Things You'll Need


Step by Step


Step 1

The first step is to turn off the pool pump to stop the flow of water through the pool filter.

Step 2

Next, you will have to relieve the pressure that has built up in the pool filter. Note the pressure on the pressure gauge. It will typically read between 15 - 20 psi. To relieve pressure turn the air relief valve on top of the filter counterclockwise. Water will spray out initially as you see the pressure on the pressure gauge go to 0 psi.

Step 3

To access the pool filter cartridge you will have to take the pool filter head off the top of the filter. Turn the locking knob counter clockwise until you feel the pool filter head is loose.

Step 4

Next lift the pool filter head off the top of the filter. It may be a little hard to lift initially as you break the O-ring seal between the two pool filter parts.

Step 5

With the pool filter head off, you will see the top of the pool filter cartridge.

Step 6

Lift the pool filter cartridge straight up to remove it from the pool filter body.

Step 7

Set the filter cartridge on the lawn and begin cleaning it with a garden hose. Use a full stray nozzle. A pressure nozzle may be too strong and will cause unnecessary wear on the pleated folds. When spraying, start at the top of the cartridge.

Please click here to view the filter flosser. 

Step 8

Work your way straight down the cartridge to work the debris down and out the bottom of the pool filter cartridge

Step 9

Rotate the filter cartridge to the next section and starting at the top work your way down again to the bottom. Continue rotating until the filter cartridge looks clean. Check inside the folds to make sure all the debris has been removed.

Please click here to view filter cleaner. 

Step 10

Some of the debris will have collected at the bottom. Spend extra time spraying out the bottom.

Step 11

When you've finished cleaning the pool filter cartridge, replace the cartridge by placing it straight down into the filter.

Step 12

It's always a good practice to lubricate the pool filter head O-ring before replacing the filter head. Lubrication will ensure a better fit and extend the life of the O-ring. Rub a thin coat of lubrication on the outside of the O-ring.

Please click here to view Magic Lube O-ring Lubricant.  

Step 13

Replace the pool filter head on top of the pool filter. Position the top so that you can read the pressure gauge.

Step 14

When replacing the filter top, watch that the O-ring doesn't bulge out of its grove. This becomes more of a problem as the O-ring becomes older and stretches. If the O-ring is not set properly the top will not close correctly and water will spray out when the pump is restarted. The O-ring should be replaced if this is a recurring problem.

Please click here to view swimming pool filters. 

Step 15

Hand tighten the locking knob clockwise.

Step 16

Turn on power to the pool pump to repressurize the pool filter.

Step 17

The air relief valve should still be open. As the pressure builds, air will be released through the relief valve. When water starts to spray out of the valve, turn the valve clockwise to close it.

Step 18

Check the pressure gauge. It typically reads between 10 - 15 psi but this will vary according to the make of pool cartridge filter or its age. This value is your system's clean filter pressure. When the pressure is 8-10 psi higher, it's time to clean your pool filter again.


(1 to 40 of 57)

 Posted: 6/25/2022 

New pool last year, today chemicals are good, but many particles floating throughout pool and it’s cloudy under water. I have good pressure. I cleaned the filter. Still have same problem. Help me

InyoPools Product Specialist  Posted: 6/27/2022 

Use a clarifier or flocculant to get rid of the floating particulates.

 Posted: 9/25/2019 

Just replaced my 4 filter cartridges and O ring. Followed the excellent instructions given. Pool pump seems to be working fine but unfortunately I am still not getting any pressure build up in my filter. Reading remains at zero. Could there be debris clogging my skimmer lines? Looking for suggestions?

InyoPools Product Specialist  Posted: 9/26/2019 

Hello Buddy - There could be a clog in the skimmer line, a suction side air leak, or a clogged/damaged impeller. Check out our video titled "How to Identify and Correct Low Water Pressure".

 Posted: 2/13/2019 

Step 10.5: Invert the filter and give it a second spray-down whilst turning to get the most stubborn particles out. This time around any residue in the bottom should be easier to remove. Ensure that you return the filter to the holder in this inverted position (I.e. switch it each time it's cleaned) to ensure even wear and tear on the filter material.

 Posted: 8/16/2018 

Hello Chris - Most laundry detergents have phosphates and will create a lot of suds. I'd recommend a phosphate free granular dishwasher detergent.

 Posted: 7/22/2018 

TSP is pretty strong stuff. How about 3 tablespoons of laundry detergent in a 5 gallon bucket? Soak one end a few hours, then the other.

InyoPools Product Specialist  Posted: 8/11/2017 

Anonymous (heavy cartridge) - A typical upper half of a filter would weigh under 10 lbs. The cartridge with water in it might weigh 15-20 lbs. A typical cartridge generally lasts 2-3 seasons and cost around $65.

Anonymous  Posted: 8/8/2017 

Wow! That looks a real pain. How heavy is the upper half of the filter housing? Was looking at replacing my old sand filter, but don't think I will now. What is the cost of each of those cartridges? Seems like it would be very expensive!

InyoPools Product Specialist  Posted: 7/8/2016 

joko3rd - The Hayward filter model number you gave me, DE4820, for a cartridge filter is actually a DE filter that uses grids. Did you mean one of the Hayward SwimClear C2030, C3030, C4030, C5030, C7030 filters that use four cartridges? The cartridges are listed in Key #13 according to the model size you have. Note: you will have to order 4 of these.

 Posted: 7/6/2016 

I have a Hayward model #DE4820 filter system. I want to replace
the 4 filters inside What is the model number for these filters.



 Posted: 6/14/2016 

Have 20x44 pool de6000 filter,pool problems very few,cartridge 22yrs old replacing now,most pools get ph 7,7.5 ph up and ph down is all I use, very little do I add at one time- its all about filtering time and chlorine,backwash several times run filter 5 min. then backwash again. all this at different times thur summer my pool is perfectly clear. pool on timer 9hrs and 2pounds powder clor bright EVERY DAY

InyoPools Product Specialist  Posted: 8/9/2015 

Kuria - Try inserting a large screwdriver between the two parts of the tank and gently prying them apart at a couple of places.

 Posted: 8/7/2015 

Hi, Very well written steps. I am trying to open my filter which is the exact model shown in the steps but the lid does not come off. Is there any trick to get it open. i am new to this.

InyoPools Product Specialist  Posted: 6/27/2015 

opening pool - There are several steps to follow when you open up a pool. See our series of guides starting with "How To Maintain A Swimming Pool Part 1 (Chemicals)" for more information.

Anonymous  Posted: 6/25/2015 

We are trying to open our pool and we've cleaned the cartridge and shocked it but the water is still not clearing. Is there something we aren't doing?

InyoPools Product Specialist  Posted: 6/8/2015 

edhoff - You might try soaking the cartridges in a TSP solution overnight. See "How To Chemically Clean a Pool Cartridge Filter", then rinsing that solution out good with a hose. Don't know if that would get everything out that would affect your pond. I don't know how fragile your pond elements are. It might be safer to use new cartridges.

 Posted: 6/7/2015 

I have a sta-rite s8m150 I want to put on my pond/ How do I remove all clorine from the cartridges?

InyoPools Product Specialist  Posted: 11/10/2014 

Filter soak - I would soak your cartridge filter in a TSP solution to get the embedded chemicals and debris out of the folds. See our guide on "How To Chemically Clean a Pool Cartridge Filter" for detailed instructions.

Anonymous  Posted: 11/9/2014 

We're cleaning our filter to put it away for winter. Is there a home solution that we can soak it in?

InyoPools Product Specialist  Posted: 3/18/2014 

experio - It sounds like your system needs to be primed. The system lines to the pump have air in them and your pump is not able to suck water into the pump. See our guide on "How To Prime a Pool Pump" for further instructions.

 Posted: 3/12/2014 

Thanks for great instructions on cleaning the pool filter. I was able to do clean filters, but my problem is that after putting everything back, I started the pump, kept the air valve open - but it seems no pressure is building up at all. Left it running for 15-20 min, and still pressure reading shows 0 psi (no outflow of air/water from the air valve)... am I doing something wrong here? Should I be checking something else?

Anonymous  Posted: 8/28/2013 

I have a 24' x 16' above ground pool that I've had problems with in terms of keeping the water chemistry balanced. Recently, I threw in apparently way too much Alkalinity Up (the container said I needed 7 lbs. for my size pool - I put in 5 lbs. but I guess you're not supposed to put it in all at once) and now the problems are worse! The cartridge filter got very clogged up with blue is the same color as the liner! Is my liner dissolving because of the chemicals - into the filter (and who knows where else?) Help!!!

InyoPools Product Specialist  Posted: 6/26/2013 

ellen - If the cartridges were filtering during those four year, four years is stretching the life or a typical cartridge. But try the TSP soaking for 24 hours. It is used to get the body and tree oils and general gunk out of the creases. Follow this up with a 10-1 muriatic acid soak for an hour to clean out the mineral build up. That should give you a much cleaner filter cartridge.

 Posted: 6/24/2013 

have an older pool with an almost unheard of filter - "modufilter", by the Wet Institute, and have finally found cartridge filters on-line that will fit. will it or will it not extend the life of the cartridge to do the TSP soaking? pool gets very little use and last set of cartridges were bought in summer of '09, so that's about four years. is that average life span or will they last longer if I TSP?
have many issues this year with cloudy water, dirty walls, sweep kind of poopy, but think all are probably due to the worn out cartridges. if not, may be back in touch. but would like your opinion of the TSP and longevity


InyoPools Product Specialist  Posted: 6/14/2013 

TRI-CLOPS - Some suggestions - If you are vacuuming very dirty water and it appears to return to the pool, check the cartridges. There is nothing in the filter to collect (and dispense) debris back to the pool except the cartridges. Make sure the cartridges are set correctly onto the bottom manifold. Check that there are no rips in any of the cartridges. Clean out the bottom of the tank. If you're vacuuming relatively clean water and it is returning dirt and debris back to the pool, have someone check your vacuum suction line. You may have developed a leak in this line that sucks in dirt when you vacuum.

Anonymous  Posted: 6/13/2013 

I just bought a house with an in ground pool. It has a TRI-CLOPS filter system. I have researched and learned how to open the pool, had a water test done added chemicals etc. The problem I am having is when I try to vacuum the pool, it goes right through the filter system and blows debris and sediment, like a gray cloud right back into my pool. I can't get the water to clear up from being cloudy, so I am stumped?? ANy ideas??

InyoPools Product Specialist  Posted: 5/20/2013 

Ahhhh - It sounds like your cartridge is getting clogged with whatever is suspended in the water. I talked to a filter rep and he suggested two partial solutions. Vacuum off the bottom for the denser particles. This all goes out the waste line - bypass filter if you can. Vacuum out 2-3 inches of water and refill. You may still have to keep re-cleaning your filter for a while but hopefully less often. Another suggestion is to use a TSP solution to help clean out the fine residue in the creases of the filters.

 Posted: 5/20/2013 

I opened our pool a little early this season and the water was more green than our grass. I shocked and used algeside and the water turned blue in hours. Unfortunately it also got very cloudy. The ph was low so I added ph up and shocked again. The chlorine was low so i added enough to bring the levels good. Once the pool was balanced I added a clarifier. After all of this the water became quite milky. The main issue i am dealing with now is my pump runs really well for 7-10 minutes then slows to a stop. I take out the filter, spray it and replace it and the same flow, great for a few minutes then trickle to nothing. The same happens with a brand new filter. I have also checked all connections on both the pump and pool. I know its the cartriges getting clogged but it must be something clear or white because while i can see a slight change im color, they look almost like new. I have been going at this for about a week now anda kinda stumped. Thanks in advance.

InyoPools Product Specialist  Posted: 1/8/2013 

mimi - Cartridges get clogged with minerals like calcium that don't rinse out with a normal hosing. Try soaking your cartridge with a TSP solution. TSP can be purchased at must local stores. Do not use muriatic acid as this tends to set the contaminates. If this doesn't work, you may have to purchase a new cartridge.

 Posted: 1/7/2013 

I just started cleaning my green pool (shock treatment, algaecide, etc). Ive cleaned the filter inside and out, did everything Ive read about, but everytime I put the filter back the pool intake stops pulling debris. I tested the pool without the cartridge and it pulls great, skimmer and all. Any suggestions??

InyoPools Product Specialist  Posted: 10/15/2012 

Eval, Yes - the Fix-a-Leak manufacturers recommend pulling the cartridge filter and circulating water through an empty tank when using Fix-a Leak.

 Posted: 10/15/2012 

I have just cleaned my cartridge filters which were quite dirty but would like to know if it's ok leaving them out for a couple of days since I need to introduce "fix a leak treatment" prior to re installing cartridges.

InyoPools Product Specialist  Posted: 8/6/2012 

artnum52 - Some of the extra chemicals used to clean a pool sometime coat the folds of a filter. Try soaking the cartridge in an diluted acid solution.

 Posted: 8/1/2012 

When I clean and replace the cartridge on my filter, it goes right to 25 -35 lbs pressure. The filter is only 4 months old. I have had to hose it done 4 times in the last 2 weeks. The pool is not green, the water is fine. What could be sending the pressure up so quickly?

InyoPools Product Specialist  Posted: 7/27/2012 

green pool - The chemicals you used to clear you pool may be clogging your cartridge. Try placing your cartridge in a weak solution of muriatic acid (1 part acid to 10 parts water) for 10 -15 minutes. Rinse well and let dry before reinstalling.

 Posted: 7/26/2012 

My pool was deep green when we tried to open it this year. I know we did not close it properly the year before. We could not get decent flow through our sand filter and the service company said the filter needed replacing and them pump was too small. We put in a new pump and a C900 filter. The pressure when a cartridge is new is about 10 PSI. WE clean it a few days later around 20. We can get the cartridge looking clean, but when I reinstall it the pressure is still around 20 psi. I've replaced the cartridge once already after less than a month. What else can I do?

InyoPools Product Specialist  Posted: 6/26/2012 

kenjen - Try getting as much of the debris out of your pool with a hand net so it doesn't keep clogging the filter. Even so you are going to have to clean your cartridge filter repeatedly (like every day) until your pool is clean of the debris. Try shocking the pool a couple of time and add algaecide if the pool contains algae. Make sure your pool chemistry is under control. See our How To Guides for more information on cleaning up a dirty pool.

 Posted: 6/23/2012 

recently i purchased a home with a pool. i never owned a pool before. been here 3 months and the pool is very dirty i noticed when we had the pump and motor on for long periods of time we had a large electric bill is that normal. i have a mytilus fmy cartridge filter NSF, challenger high head pump me plus pac fab 1, ac smith centurion switchless motor, model t104p3 24 hour dialtime switch, challenger pac-fab 1 hp self prime pump. i am not sure if previous also had a heater. i am not sure if all items where changed before move. should i upgrade everything

InyoPools Product Specialist  Posted: 6/1/2012 

DLHall - Organic stains are difficult to remove. Try rubbing a Vitamin C tablet on a test spot. If that works, buy ascorbic acid to remove the stains.