How to Clean Your Pool Filter Cartridges — and When It's Finally Time to Replace Them

Your pool filter cartridge is doing a lot of quiet, unglamorous work every single day. It's catching sunscreen, algae spores, dirt, fine debris, and everything else that ends up in your pool before any of it has a chance to make the water cloudy or unsafe. When it's clean and functioning properly, you barely notice it. When it's not — your pump works harder, your water gets hazy, and your chemical costs can start climbing for no obvious reason. At Aqua Pool Supply, we stock genuine replacement cartridges for the most common Hayward and Pentair filter systems at prices that are hard to beat online — and this guide will help you know exactly when it's time to order one. 

Why Keeping Your Filter Cartridge Clean Actually Matters

A lot of pool owners rinse their cartridge when they remember to, and replace it when it looks really bad. That approach works — but it's not the most efficient way to run your system. Here's what's actually happening inside your filter housing when the cartridge gets dirty:

Your Pump Has to Work Harder

As debris builds up in the pleats of a cartridge filter, water flow becomes restricted. Your pump has to push harder to move the same volume of water through the system, which increases energy consumption and puts extra strain on the motor and impeller over time. Consistently running with a dirty cartridge is one of the quieter causes of premature pump wear.

Filtration Quality Drops Off

There's a common misconception that a dirty cartridge filters better because more is "caught" in the fabric. In reality, once a cartridge is overloaded, fine particles start bypassing it entirely and returning to the pool. If your water is looking slightly hazy even with correct chemistry, a clogged cartridge is often the first thing to check.

Your Chemicals Work Less Efficiently

When circulation is reduced and particulates aren't being removed properly, chlorine and other sanitizers have to work harder to maintain safe water quality. Pool owners running dirty cartridges often find themselves adding more chemicals than they should need — which adds up fast over a swim season.

How Often Should You Clean Your Pool Filter Cartridge?

The standard rule of thumb: clean your cartridge when the pressure gauge on your filter reads 8–10 psi above the clean baseline. That's the most reliable indicator regardless of how the water looks or how long it's been since the last cleaning. Write down your system's clean pressure the next time you install a fresh or freshly cleaned cartridge — that number is your benchmark going forward.

For most residential pools, that typically means:

• High-use pools or pools near trees/landscaping: Every 2–4 weeks during swim season
• Average residential pools: Every 4–6 weeks during swim season
• Low-use or covered pools: Every 6–8 weeks or as the pressure gauge indicates
• After heavy use, algae treatment, or major storms: Clean immediately regardless of schedule

How to Rinse a Cartridge Properly

Turn off the pump, release pressure from the filter, and remove the cartridge. Use a garden hose with a straight nozzle (not a pressure washer — the pressure can damage the pleats) to rinse from top to bottom at an angle, working debris out of the folds. Rotate the cartridge as you go. A dedicated cartridge cleaning wand makes this significantly easier and faster if you haven't used one. Let the cartridge dry fully if you have a backup, or reinstall once rinsed and check that pressure returns to baseline.

For a deeper clean, soak the cartridge overnight in a diluted filter cleaning solution or a 1:20 muriatic acid mixture to break down calcium scale and oils that water alone won't remove. Rinse thoroughly afterward before reinstalling.

When Is It Time to Replace Instead of Clean?

Cartridges don't last forever — and trying to squeeze extra seasons out of one that's past its useful life will cost you more in chemicals, energy, and frustration than the cartridge itself is worth. Here's what to look for:

• The pressure gauge returns to elevated levels quickly after cleaning — if you clean the cartridge and pressure spikes again within a few days, the pleats are likely so loaded with fine debris or oils that rinsing can no longer restore proper flow
• Visible damage to the pleats — tears, collapsed folds, cracked end caps, or a deformed core all mean the cartridge is no longer filtering properly regardless of how clean it looks
• Persistent hazy water with correct chemistry — if your chlorine, pH, and alkalinity are all in range but the water stays cloudy, the cartridge may be bypassing fine particles
• The fabric has a gray or brown stain that won't rinse out — this usually indicates embedded oils, sunscreen residue, or mineral buildup that has permanently reduced the cartridge's filtration capacity
• It's been 1–3 years since the last replacement — most quality cartridges last 1–3 years depending on pool usage and how consistently they're cleaned. If you can't remember the last time you replaced it, that's probably your answer

Our Best-Selling Pool Filter Cartridge Replacements

We stock the most common replacement cartridges for Hayward and Pentair filter systems — all genuine OEM and certified cartridges, in stock and priced below what most retail outlets charge. Here's what we carry and what each one fits.

Pleatco PA120 — Hayward Star-Clear Plus C-1200 (120 sq ft Single Cartridge)

The Pleatco PA120 is a high-quality replacement cartridge for the Hayward Star-Clear Plus C-1200 filter — one of the most commonly installed residential single-cartridge filters in Arizona and Nevada. It offers 120 square feet of pleated polyester filtration surface, which is a solid capacity for a single-element design, and it's built to handle repeated cleaning cycles without losing structural integrity. Pleatco is owned by Pentair and manufactures to the same OEM standards, so you're getting genuine-quality filtration — not a generic knock-off.

• Fits: Hayward Star-Clear Plus C-1200 and comparable 120 sq ft applications
• Filtration Area: 120 sq ft
• Configuration: Single cartridge
• NSF Certified: Yes

Regular Price: $99.99  |  Our Price: $84.99  |  Instant Savings: $15.00
→ Shop the Pleatco PA120 Replacement Cartridge

Hayward CX200XRE — C200S Replacement Cartridge Element

The Hayward CX200XRE is the genuine OEM replacement cartridge engineered specifically for the Hayward C200S filter system. If you're running a C200S and it's time for a new element, this is the exact part Hayward designed for it — precision fit, NSF certified, and built for multi-season durability. It delivers strong first-pass debris capture and is designed to maintain hydraulic efficiency across full filter cycles, which means less pump strain and longer intervals between pressure spikes.

• Fits: Hayward C200S filter systems
• Configuration: Single cartridge element
• OEM: Genuine Hayward part
• NSF Certified: Yes

Our Price: $141.00
In stock and ready to ship.

Hayward CX880XREPAK4 — 425 sq ft Replacement Cartridges, 4-Pack

The Hayward CX880XREPAK4 is the genuine 4-pack replacement for Hayward's multi-cartridge filter systems that use 425 sq ft elements. Multi-cartridge filters are extremely common on larger residential pools — if your Hayward filter housing holds four cartridges, this is your pack. Each cartridge is precision-engineered with a molded core for structural stability and maximum hydraulic efficiency, meaning your pump flows better and runs longer between cleanings.

One note on replacement timing with multi-cartridge systems: always replace all four cartridges at the same time. Mixing old and new cartridges creates uneven flow distribution across the elements, which reduces overall filtration efficiency and shortens the life of the new cartridges you just installed.

• Fits: Hayward multi-cartridge filter systems requiring 425 sq ft elements
• Filtration Area: 425 sq ft per cartridge
• Pack: 4 cartridges
• OEM: Genuine Hayward part
• NSF Certified: Yes

Our Price: $329.95
In stock and ships fast.

Pentair Clean & Clear Plus 420 Cartridges — 4-Pack (179135)

The Pentair Clean & Clear Plus 420 4-Pack (179135) is the go-to replacement for one of the most widely installed residential cartridge filters on the market. If you have a Pentair Clean & Clear Plus 420, this is your cartridge pack — four non-woven polyester cartridges certified to NSF/ANSI Standard 50 and factory tested to Pentair's OEM specifications. At our current price, you're saving over $110 off retail on a full set of four, which makes this a smart buy anytime you're planning ahead for the season.

One thing worth noting: due to Pentair's recent acquisition of Pleatco, these cartridges may arrive with Pentair branding, Pleatco branding, or both. The part is the same regardless of what the box says.

• Fits: Pentair Clean & Clear Plus 420 filter systems
• Pack: 4 cartridges
• OEM: Genuine Pentair/Pleatco
• NSF/ANSI Standard 50 Certified: Yes

Regular Price: $349.99  |  Our Price: $238.99  |  Instant Savings: $111.00

Pentair Clean & Clear Plus 520 Cartridges — 4-Pack (179136)

Step up to the larger system and the Pentair Clean & Clear Plus 520 4-Pack (179136) is your replacement. Same OEM quality and NSF certification as the 420 pack, sized for the larger Clean & Clear Plus 520 filter housing. We're currently running this set at over $100 off retail, which is one of the better deals on Pentair cartridges you'll find right now. Same Pentair/Pleatco branding note applies here as well.

• Fits: Pentair Clean & Clear Plus 520 filter systems
• Pack: 4 cartridges
• OEM: Genuine Pentair/Pleatco
• NSF/ANSI Standard 50 Certified: Yes

Regular Price: $399.99  |  Our Price: $298.99  |  Instant Savings: $101.00

Don't See Your Cartridge Listed?

We carry a full selection of pool filter replacement cartridges for Hayward, Pentair, Waterway, and more. If you're not sure which cartridge fits your filter or need help identifying your model, stop in or give us a call — we're in Phoenix, Chandler, Scottsdale, and Las Vegas and handle cartridge questions every day. Bring your old cartridge in if you can — matching by dimensions is the fastest way to get the right fit.