Monday, February 14, 2011

How To Clean Your Own Hayward Pump Cartridge Filters

One of the chores of being a pool owner in dusty Arizona, is that you either have to pay a pool service to clean your filters at least annually, or save the $500 or $700 they'll charge, and do it yourself.  Hayward pumps and Shasta Pools recommend cleaning the filters every 6 months, in the Spring and Fall, if your pool is heavily used.  In 2007, 08, and 09, I followed that recommendation, and found that the main filter body experienced a 10 psi decrease in head pressure immediately after each cleaning.  This made sense, since with less contamination on each filter, the pump did not need to work as hard to push water through them.

Well last Fall, with the rescue mission to go get Nathan Jr, and the short stay we had with our son staying with us, I did not have a chance to do a Fall cleaning, so the weekend before I headed to PA and NY, I took out about 3 hours to do the annual filter maintenance.  I'll try to explain here, the process I use, and you can attempt the same at your home if you are mechanically adept.  If you're not adept, or don't want to spend the time, this is what your pool service professional might be doing - or they might be raping you and charging you exorbitant rates to change out each of the eight cartridge filters that go for $50 at Home Depot, or $60 at the Shasta store.
 You need the following: 
- ratchet and socket
- a good screw driver (I use Craftsman)
- something to sit on (I use a old kitty litter pail)
- something to rest the filters on, instead of gravel or grass (I use an old cookie sheet)
- a hose, with a nozzle
- a tube of silicone grease
- 2 or 3 small disposable rags, to wipe silicone off your fingers
- patience
- upper body strength and good lifting technique
- a day with ambient temperatures above freezing

Find a place in your yard that has a 6 to 8 foot "splash zone" where you won't be spraying your home, it's foundation, or pH sensitive shrubbery or desert plants, a few feet away from the curb (there will be over-flow of some water that will run into the street).  I used to clean the filters on the driveway,. but I moved to the easement between my property and the neighbor's this year for the cleaning. 

1. Make sure your pump is turned off.  Disconnect the power, and make sure it won't automatically turn on mid-way through cleaning.

2.  Valve your intake to draw from the bottom of the pool and not from the skimmer.  

3.  Relieve the pressure on the large filter body.  behind the pressure gauge on the top of the large filter body, you'll find a little relief valve that can bleed the air away safely.  Loosen it, and you'll hear hissing from the valve, and "glug glug glugging" as water bubbles up through the system.  Both of these are "normal" sounds.

4.  Remove the protective thread guard cap and don't lose it.  You'll need to put it back in place when you are done. 

5. When the large filter body pressure relief valve reads "zero" ("0"), you can loosen the spring loaded nut with a ratchet and socket.  Try to maintain the nut-thrust washer-spring-washer assembly stacking, after removing it from the T-bolt, so you can easily remember how it goes back on.

6.  Remove the T-bolt, and then give the filter body a large bear hug.  With a twisting and lifting motion, you can lift the upper filter body off, and set it aside close by in the shade (leave it in the sun, if you want to burn yourself when you reassemble on the heated plastic). Be careful as you lift the filter body, as there is silicone lubricant all along the mating o-ring seat, and you don't want to wipe that silicone onto the paper filters and contaminate them, or they'll turn brown over-time, as evidenced in the above photo.  The upper filter body weighs about 30 lbs - not so heavy - but it is cumbersome and somewhat unwieldy, if you don't have a 6 foot reach with which to embrace the large plastic cylindrical filter body.

7.  Remove the filters, one by one or two by two, whichever works best for you.  The 4-leaf-clover end caps are idiot-proofed, and cannot be incorrectly installed.  They need to be removed and cleaned as well.

8.  Carry the dirty filters away from your pool, to the cleaning area - I take them two by two, one in each hand.  Crowding your cleaning area with lots of dirty filters can cause the cleaned ones to get back-splashed, and since they are expensive, you don't want to leave them curbside for an enterprising entrepreneur to snatch up when you are traversing back to your back yard (ahhh, city life!).

9. Now the blasting can begin.  Make sure the pan you are using angles away from your feet, or you'll be soaked by the time you are done cleaning.  Place each filter on the pan, one at a time, and angle the filter so that gravity helps your sprayed water stream to encourage dirt particles to run Down the filter and onto the ground.  You'll find insect parts, hair, small seeds, disintegrated poly styrene cooler left over tiny balls, and a variety of small particles that have made it though the trash screens in the pump and pre-filters washing out onto the ground. Blast from the outside, at a downward angle.  See the photo, to illustrate my point.

The water and dirt particles that first come off the filters will be chlorinated, but they will decrease in ion content rapidly, as the hose water floods over the filter paper.  You'll be able to visibly see dirt, mud, thorax, wings, insect heads, hair, washing  down and off the filters over the pan (or driveway).  This is good and fine and shows that your blasting is having a positive effect.

10.  After blasting from top to bottom, flip the filter, and blast again from top to bottom, rotating in 10 to 15 degree increments.  This will help to dislodge large particles that have worked their way between the tight folded mesh paper.  Repeat this 7 more times, one flip on each of the 8 filters.

11.  Use your screw driver to gently loosen the drain plug on the filter body.  DO NOT over-tighten.  I over-tightened multiple times in 2007 when I first began doing my own filter maintenance.  It needs very little torque to remain in place.  Over tightening will cause the large white drain plug to BREAK and LEAK, and they cost $8 each to replace.  Don't use a pipe wrench to tighten this, unless you are very very delicate with a large pipe wrench.  About 20 gallons of water will come gushing out of the lower half of the filter body. 

12.  As the waster gushes out, each inside and encourage gravel and heavy debris to flow out the drain.  You can do this carefully with your hand, making sure not to brush the silicone covered O-ring to your waist.  A hose can be used as well, to blast them out.  You want to get as much gravel out as you can, before you re-assemble.

 13. There's a wing nut equipped drain plug on most Hayward pump bodies as well.  Loosen it by hand and encourage any small gravel (pre-pump) out the small drain hole also.  DO NOT use a large tool to tighten this wing nut.  Designers put in wing nuts so that the "average human" can tighten and loosen by hand, not with a wrench or pliers.  You'll damage the expensive pump body if you over-tighten.

14.  Blast the plastic and wire mesh pre-filters baskets with hose water.  Do Not "thump" them against the ground or your hand or anything solid, as the baskets are not made to survive IMPACT.  They'll break, or dent, and then you'll be out dozens or hundreds of dollars in replacement costs.  I did not destroy one, but I DID crack one of the pump basket's plastic strands slightly, and treat them more gingerly now.

15.  Reassemble the 8 filters back into the cleaned filter body.  I try to place the darkened, contaminated parts, away from the intake where incoming chlorine concentrations are highest, especially after shocking the pool.  You can see the dark spots in the photo here, some of which were cause by silicone contamination, and some of which were caused by high concentrations of chlorine adjacent to the inlet.  By rotating the filters this way, you can extend their lives several years longer than Shasta would like (avoiding the $60 / each replacement costs).  [Follow the pipe from the pump to the filter body, to locate the filter body inlet]

16.  Reapply a thin coat of silicone to the main filter body o-ring and o-ring mating surfaces.  Apply a thin coat of silicone to the pump pre-filter body basket cover seals as well, using your finger to spread the new silicone around evenly.  Clean your hands on the rags after applying, and keep the seals clean as the silicone will attract debris readily if carelessly left on the ground.

17.  Carefully, gently, slowly, lower the large main filter body down over the newly cleaned and reassembled filters, making sure not to "drag" the silicone covered edge along the clean filters.  Seat the upper body onto the o-ring, and do a small "rotation" or 5 or 10 degrees, to fully "seat" the o-ring into its groove. 

18.  Reassemble the T-bolt, spring & washer assembly, and tighten the assembly using the socket and ratchet.  Continue until the spring is fully compressed.  It will be loud, as the tightening progresses, but that's good.  All that sound represents friction, and that friction (and the spring) will help prevent the assembly from loosening up on its own.  See the video below, to illustrate my point.  

19.  Get a bucket of water.  You can draw it out of the pool, quickly, or you can fill up a bucket with a garden hose,  it you want to waste more water - you just blasted several hundred gallons down your drive way, or into your water tolerant shrubs.  I use the same bucket I sat on while blasting the filters.  Dump the bucket of water into the pump pre-filter body, and QUICKLY put the lid on, before all the water "glug glugs" out of the pump into the rest of the system.

20. Do the same thing (#19) on the wire basket pre-filter "leaf vac" if your system is equipped with one.  Much of the water will rush out of the system and back into the pool, but using the bucket to "prime" each pre-filter body helps to reduce the strain on the pump.

21.  Check the integrity of all your seals, making sure you don't have any caps or plugs out of place.  Loosen the pressure relief valve on the top of the main filter body, to help the pump from fighting against excessive back pressure.  Some schools of thought say to leave the pressure relief valve closed until you see large sets of bubbles coming out of the nozzles in the pool, but I think the pump is working hard enough to draw in water.  Further loading it with more head pressure resistance doesn't make good fluid dynamic sense to me (blog visitors are encouraged to rebuttal in the comment section, if you disagree).

22.  When you have checked everything, you can re-energize your system, and start your pump.  You'll hear air rushing out of the filter body, and you'll see water rushing in through the sight glasses into the pre-filter chambers as the pump works to load up the system.  Out in the pool, you'll see large plumes of air jetting out of each pool floor nozzle, as the trapped air is driven through the system.  When the main filter body is FULL of water, it will begin spraying out of the pressure relief valve.  Close the valve with your fingers - do not use tools to torque it further.  The pump body and leaf vac sight glasses should fill up within a minute or two.  If they don't fill up, you've got a leaking seal somewhere.  You'll need to de-energize, disassemble, and see if you've flattened or rolled a seal somewhere.

Each filter takes me about 20 minutes to blast.  Each pre-filter basket takes 5 or 10 minutes, depending on how much hair and debris are lodged into the mesh.  Total start-to-stop time takes me 3 to 4 hours.  Kudos to you if you do it faster (again, comments are welcomed), or better.  A successful cleaning drops the differential pressure across the filters by approx 10 psi, as evidenced on the filter body gauge.  When dirty, I run 20 to 25 psi (13.8 to 17.2 MPa).  When clean, 10 to 15 psi (6.9 to 10.34 MPa), cycling up and down.

I hope this helps.  If you have any questions,  or suggestions, do not hesitate to make a comment here.  The "How To" postings get some of the most hits here on JustJoeP.


  1. Whatever happened to sand filters and diatomaceous earth filters? Sand filters used to be built to last forever and required simple maintenance. The earth filters were generally not built as well but obviously much finer filtering. I always thought a 2-stage filtering setup (sand first) would work well, but never saw anyone implement it. Is this cartridge system the de facto standard now?

  2. I believe each is still available. Diatomaceous earth I have seen at pool stores, and I've helped Dr Desert Flower's scientist colleagues (some who have no mechanical ability) trouble shoot their sand filter systems. But Hayward obviously wants to make more money on replacement parts for cartridge filters, and Shasta (considered a generally "higher class" and more expensive pool installer) loves to use Hayward.

    So you can spec out a system with sand or crushed up diatoms, and have it installed still, but in Arizona, the cartridge scheme appears to be ubiquitous.

  3. Every time my pool cartridge filter gets dirty, i have to call up a professional to get it cleaned or replace it with a new one. By reading your post, i think it would not be so difficult to clean it. You have given the easiest way to clean it.. thanks for this post, it will surely help me.

  4. Great idea! However, you're not quite done after you install the filter.
    Once the filter is installed you have to start thinking about getting replacement water filter cartridges. A water filter is a lot like the filter for your air conditioner, it can only filter so much.

  5. yes Then, and as the blog entry stated: "Hayward pumps and Shasta Pools recommend cleaning the filters every 6 months, in the Spring and Fall, if your pool is heavily used. In 2007, 08, and 09, I followed that recommendation, and found that the main filter body experienced a 10 psi decrease in head pressure immediately after each cleaning. This made sense, since with less contamination on each filter, the pump did not need to work as hard to push water through them."


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