How to clean a pool cartridge filter
How to clean a pool or spa cartridge filter in Australia, in a concrete or fibreglass pool alike: the steps from four filter makers’ manuals, the gauge rise that says it is time, when to soak instead of hose, what cleaner costs, and the pressure test that says the cartridge needs replacing, before you pay the price of a new element or claim on its warranty.
How do I clean my pool cartridge filter? Pump off, air bleed open until the gauge reads zero, then lift out the cartridge and hose between the pleats with a garden-hose nozzle, never a pressure washer. Clean when the gauge is 15–50 kPa above its clean reading, by Australian maker; one says never go over 12 months between cleans.
The short answer
- The trigger: four cartridge filter makers’ manuals say clean when the gauge rises 15–20 kPa, more than 20 kPa, 50 kPa, or 8–10 psi (about 55–69 kPa) above the clean reading. Your own manual decides.
- The method: pump off, valves closed, air bleed open until the gauge reads 0, lid off, cartridge out, hose between the pleats inside and out, o-ring cleaned, reseat, restart and bleed the air.
- Not a pressure washer: two manuals say high-powered water jets can damage the element and a garden hose with a nozzle does the job, although one of them also lists a high-pressure cleaner in its own maintenance table.
- The soak: 15 minutes in mild chlorine and warm water in two manuals, overnight in cleaning compound in a third, which also says intervals between cleans should never exceed 12 months.
- Replace, do not clean, when a freshly cleaned cartridge still reads more than 30–40 kPa above the filter’s new pressure; on a filter that started at 60 kPa, that is above 90–100 kPa.
| Step | Trigger | What the manuals say to do | Time and cost | Source |
|---|---|---|---|---|
| 1. Read the gauge | Fortnightly; write down the pressure when the filter is new or freshly cleaned | The starting number every other row is measured from | Free | Two cartridge manuals from one maker group |
| 2. Hose it | Rise of 15–20 kPa (one manual), more than 20 kPa (a second), 50 kPa (a third), 8–10 psi, about 55–69 kPa (a US manual) | Garden hose with a nozzle, into the pleats, inside and out; not a pressure washer | Minutes and water | Four makers’ manuals |
| 3. Soak it | Periodically, and one maker says never more than 12 months between cleans | 15 minutes in a mild chlorine and warm-water solution (two manuals), or overnight in a cartridge-cleaning compound (a third) | $29.00–$30.00 for a cleaner at two retailers (retailer-published) | Three manuals; two retail listings |
| 4. Replace it | Freshly cleaned, it still reads more than 30–40 kPa above the new-filter pressure; or torn pleats | A new element; the life and price are on our filter pages | See the cartridge cost page | Two manuals’ annual check |
How do I clean my pool cartridge filter?
The steps below follow one maker’s XC-series manual, with the points where other makers differ. The filter is under pressure while the pump runs, and that manual warns that trapped air can blow the lid off, so the first three steps are about getting the pressure out.
- Turn off the pump and anything that can start it, such as a timer or automation.
- Close the suction and return valves if your system has them, so the pad does not flood.
- Open the air bleed valve on the lid about three-quarters of a turn and wait until the pressure gauge reads zero. Drain the tank from the cap at the bottom if it has one.
- Undo the locking ring and lift the lid off. The manual says never to loosen the ring with the pump on.
- Lift out the cartridge and hose it with a garden hose and nozzle, working into the pleats. A US maker’s manual says to spray the outside and the inside and turn the cartridge over several times as you go.
- Check the lid o-ring for cracks and wear and lubricate it with a non-petroleum lubricant only; the US manual says petroleum-based lubricants damage the rubber.
- Seat the cartridge on its bottom spigot, refit the lid until the ring clicks, open the valves, start the pump, bleed the air from the lid and write down the new clean pressure.
Most owners do this themselves; the only cost is water and your time. If the cartridge is beyond cleaning, what a replacement cartridge element costs is set out separately.
Before opening a cartridge filter, turn the pump off and open the air bleed until the gauge reads zero; pressure left in the tank can blow the lid off.
When should I clean my cartridge filter? The gauge card
When the gauge says so, and the makers disagree about the number. That is the useful thing to know, because a figure from someone else’s filter can have you cleaning twice as often as you need to, or half as often.
Worked on one filter. Take a filter that reads 60 kPa clean, the example a second maker uses. Each manual’s rule puts the cleaning point here:
| Manual | Its rule | Clean this filter at |
|---|---|---|
| One maker’s CF manual | Rise of 15–20 kPa | 75–80 kPa |
| The same group’s XC manual | Rise of more than 20 kPa | above 80 kPa |
| A second maker’s manual | 50 kPa above operating pressure | 110 kPa |
| A US maker’s manual | 8–10 psi above starting pressure | about 115–129 kPa |
The same dirty cartridge is “due” anywhere from 75 to about 129 kPa. Use the rule printed in your filter’s manual, and use your own clean reading, not a number from a forum. Two manuals say to check the gauge fortnightly. Both also say salt water can shorten a gauge’s life, so if the reading never moves, check the gauge before trusting it.
If the pressure climbs again within days of a clean, the cartridge may not be the problem: the pump may be too big for the filter. Sizing a pool filter to the pump covers that.
On a cartridge filter that reads 60 kPa clean, the makers’ cleaning points range from 75 kPa to about 129 kPa, so use the rule in your own filter’s manual.
Should I soak my cartridge filter, and in what?
Hosing removes the dirt you can see; oils, sunscreen and fine debris stay in the fabric. The makers’ answer is a periodic soak, and they give two different ones:
- Mild chlorine and warm water, 15 minutes, then hose off: two cartridge manuals from one maker group. Both add that purpose-made element cleaners are sold by pool shops.
- Overnight in a cartridge-cleaning compound, to remove what hosing leaves: a second maker’s manual, which says intervals between cleans “should not exceed a period of 12 months in any instance”.
What it costs. Two retailers listed spray-on or soak cartridge cleaners at $29.00–$30.00 on 20 October 2026 (retailer-published). One cleaner’s own listing says to soak overnight and clean every 2–4 weeks; that is a seller’s instruction for its product, not a filter maker’s, and it is far more often than any filter manual we read asks for.
Two cautions. If you soak in chlorine, do not then put the cartridge, or the bucket, near an acid cleaner: Safe Work Australia’s guidance says pool chlorine and acid together release poisonous chlorine gas. And if your pool runs a non-chlorine (biguanide) sanitiser, a US maker’s manual warns that a TSP-type cleaner used before the sanitiser’s film is stripped turns into a gum that cannot be removed, and the cartridge has to be replaced. Use the cleaner your sanitiser’s maker specifies.
Hose a pool cartridge filter when the gauge rises; one filter maker says never go more than 12 months between cleans.
How often should pool cartridge filters be replaced?
When cleaning stops working, not on a date. Two manuals give the test: once a year, compare the pressure of a freshly cleaned cartridge with the filter’s pressure when new, and replace the cartridge if it is more than 30–40 kPa higher. On the 60 kPa filter above, a cleaned cartridge reading over 90–100 kPa is finished. Damaged pleats mean replacement at any age, both manuals say.
The life figures makers publish, a US maker’s “average media life of three (3) years”, and the warranty on the housing are on how long a pool filter lasts; this page does not repeat them.
If you are building or re-equipping, a cartridge filter produces no backwash water, which matters where disposal is restricted. Ask each quote for the filter model, its rated flow and the element’s part number, then compare pool quotes on the same plant. Pool businesses are listed in Sydney, Melbourne and Perth.
Common questions
How often should pool cartridge filters be cleaned?
Can I pressure wash my pool cartridge filter?
What do I soak a pool filter cartridge in?
How often should pool cartridge filters be replaced?
Why does my cartridge filter pressure stay high after cleaning?
Sources
- Cartridge filter maker’s installation and operating instructions, CF series: cleaning steps, 15–20 kPa, maintenance schedule (vendor-published, retailer-hosted)
- Cartridge filter installation and operation manual, XC series: depressurising, cleaning, 30–40 kPa replacement test (vendor-published, retailer-hosted)
- Second cartridge filter maker’s manual: clean at 50 kPa above operating pressure; overnight soak; 12-month maximum (vendor-published)
- US cartridge filter maker’s owner’s manual: 8–10 psi rule, hosing, lubricant, average cartridge life, biguanide caution (vendor-published)
- Online pool supplies retailer: spray-on cartridge filter cleaner, $29.00 (retailer-published, read 20 October 2026)
- Online pool supplies retailer: instant filter cleaner 500 mL, $30.00 (retailer-published, read 20 October 2026)
- Online pool retailer: soak-type filter cleaner 500 g, $29.99; label says soak overnight, every 2–4 weeks (retailer-published, read 20 October 2026)
- Safe Work Australia: Storage of swimming pool chemicals, information sheet (chlorine and acid release chlorine gas)
General information only, current at 2026-10-20. Pool rules differ by state and by council, and penalty amounts are updated regularly. Confirm your own obligations with your council or a registered inspector before acting.
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