How to Clean a Pool Filter Cartridge (The Right Way)
Your pool filter cartridge is the one thing standing between crystal-clear water and a green swamp. But here’s what most pool owners get wrong: they wait way too long to clean it, then wonder why their water looks off even with perfect chemical levels.
A dirty cartridge restricts flow, raises your pump’s energy consumption, and lets fine debris slip right back into your pool. The fix takes about 20 minutes and costs almost nothing if you do it yourself.
How Often Should You Clean a Pool Filter Cartridge?
The short answer: every 2-4 weeks during swimming season, or whenever your filter pressure gauge reads 8-10 PSI above its clean baseline.
Write down the PSI reading right after you install a clean cartridge. That’s your baseline. When the gauge climbs 8-10 PSI above that number, the cartridge is clogged enough to restrict flow and needs cleaning.
- Water clarity is declining despite normal chemical levels
- Your pump is working harder (louder than usual)
- Water flow from return jets feels weak
- The skimmer isn’t pulling with its usual suction
Step-by-Step: How to Clean a Pool Filter Cartridge
Step 1: Turn Off the Pump
Never remove a cartridge while the pump is running. Shut it off at the breaker or timer, not just the switch.
Step 2: Release Pressure and Open the Filter Housing
Open the air relief valve on top of the filter to release trapped pressure. Once fully released, remove the clamp band or lock ring and carefully lift off the top.
Step 3: Remove the Cartridge
Lift the cartridge straight out. It’ll be heavier than you expect because it’s waterlogged. Set it on a flat surface like a driveway or patio.
Step 4: Rinse With a Garden Hose
Using a garden hose with a nozzle attachment, spray each pleat from top to bottom at a 45-degree angle. A filter cleaning nozzle makes this much faster. Never use a pressure washer — it damages the filter fabric.
Step 5: Soak in Filter Cleaning Solution (Deep Clean)
Every 1-3 months, give your cartridge an overnight soak. For oily buildup: TSP solution (1 cup per 5 gallons). For mineral scale: Muriatic acid wash (1:20 ratio, acid to water). Never mix acid and TSP.
Step 6: Rinse Again and Inspect
After soaking, rinse thoroughly and inspect: intact pleats, no tears, no cracked end caps. If damaged, it’s replacement time.
Step 7: Reassemble and Record
Reinstall the cartridge, close the housing, restart the pump, purge air via the relief valve, and record the new clean pressure reading.
When to Replace Your Pool Filter Cartridge
Plan on replacing every 1-2 years. Replace immediately if the fabric is torn, end caps are cracked, cleaning no longer restores baseline pressure, or pleats are permanently flattened.
Use our Pool Filter Size Calculator to find the right replacement.
Pro Tips for Longer Cartridge Life
Rotate two cartridges. Alternate them so one soaks while the other runs. Shower before swimming. Sunscreen and body oils are the #1 cartridge killer. Keep chemistry balanced. Use our Calcium Hardness Calculator to prevent scale buildup. Optimize pump runtime. Use our Turnover Rate Calculator to minimize unnecessary filtration.
Recommended Products
As an Amazon Associate, we earn from qualifying purchases.
Pleatco Filter Cleaning Wand (~\) — Fan spray nozzle that gets deep between pleats.
BioGuard Strip Kwik Cartridge Cleaner (~\) — Overnight soak formula for oils and organic buildup.
Hayward CX1200RE Replacement Cartridge (~\) — Fits Hayward C1200 Star-Clear Plus filters.
Pleatco PA120 Replacement Cartridge (~\) — Universal fit aftermarket alternative.
Calculate It Instantly with Pool Chemical Calculator
Stop guessing with your pool chemistry! The Pool Chemical Calculator app tells you exactly how much of each chemical to add.
Download for Android | Download for iPhone/iPad | Use Online
Frequently Asked Questions
Can you clean a pool filter cartridge with bleach?
You can, but it’s not ideal. Diluted bleach kills algae but doesn’t dissolve oils or mineral scale, and degrades the fabric faster than dedicated cleaners.
Can you put a pool filter cartridge in the dishwasher?
No. The heat damages the fabric and warps end caps.
How long does a pool filter cartridge last?
With regular cleaning, 1-2 years. Heavy use pools may need replacement annually.
What PSI means my cartridge needs cleaning?
8-10 PSI above your clean baseline. Most residential filters run 10-15 PSI clean and need attention at 18-25 PSI.
Is it better to clean or replace a pool filter cartridge?
Clean it as long as it restores normal pressure. Replace when cleaning no longer works or you see physical damage.
