The Unsung Hero of a Clean Pool: Why Cartridge Filter Cleaning Matters

If you own a swimming pool, you likely know the basics of keeping it clean: scoop out the leaves, keep the water chemistry balanced, and run the pump. But there’s a less glamorous hero working behind the scenes to keep your water crystal clear—your pool filter.

And if you’re like many homeowners in Santa Rosa or Sonoma County, chances are your pool is equipped with a cartridge filter.

What Does a Cartridge Filter Do?

A cartridge filter works by trapping debris, dirt, oils, and other contaminants as water passes through it. Inside the tank, pleated polyester or similar synthetic material catches fine particles down to 10-20 microns. The larger the surface area of the pleats, the more efficient the filter.

Cartridge filters are ideal for residential pools in Santa Rosa due to their high filtration efficiency, relatively low maintenance, and energy-saving design—there’s no need for backwashing, which saves water and lowers system strain.

Why Regular Cartridge Filter Cleaning Matters

Over time, dirt, body oils, sunscreen, and fine particles clog up the pleats of your cartridge. A dirty cartridge restricts water flow, strains your pump, and reduces your pool’s circulation efficiency. This can lead to cloudy water, algae blooms, increased chemical usage, and even equipment damage.

According to industry experts, neglecting filter maintenance is one of the most common causes of poor water quality.

A clean filter:

• Improves water clarity

• Increases circulation and efficiency

• Reduces stress on your pool pump and motor

• Helps maintain balanced water chemistry

• Extends the life of the filter and pump

Cleaning your filter is also a chance to visually inspect it for cracks, worn-out pleats, or collapsed end caps—which can cause the filter to lose its effectiveness entirely.

How Often Should You Clean a Cartridge Filter?

The general rule of thumb is at least every 6 months, or more frequently if your pool sees heavy use or is surrounded by trees and landscaping that drop debris.

However, don’t rely solely on a calendar. Use the pressure gauge on your filter tank:

• When the pressure rises 8-10 PSI above the clean baseline, it’s time to clean.

Some homeowners keep a maintenance log to track pressure readings and cleaning intervals, which can help identify changes in performance over time.

What Happens If You Don’t Clean It for a Long Time?

While it may be tempting to let filter maintenance slide, putting it off for too long can cause irreversible damage. When filters go uncleaned for extended periods, several issues can develop:

• Permanent clogging: Oils and fine debris harden over time, embedding deep into the pleats. Once this happens, even soaking in chemical cleaners may not fully restore the filter’s flow or performance.

• Structural damage: Overloaded filters can deform under pressure. The pleats may collapse, the core can crack, or the end caps can separate, rendering the filter ineffective.

• Reduced filtration efficiency: A neglected filter won’t return to its original level of filtration even after cleaning. Microscopic debris can get lodged so deeply that the filter can no longer perform at peak efficiency.

The longer a filter is left dirty, the more likely it is that you'll need to replace it prematurely—often well before the 3 to 5 year mark you'd expect with proper care.

When to Clean vs. When to Replace Your Cartridge Filter

Cleaning a cartridge filter is routine maintenance—but knowing when cleaning is no longer enough is just as important.

Clean your filter if:

• The pressure has increased 8-10 PSI above normal

• Water is cloudy but improves after a rinse

• It’s been 4-6 weeks since the last cleaning

• There is visible buildup of debris, oils, or scale

Replace your filter if:

• You notice visible tears, holes, or frayed fabric

• The pleats are flattened, misshapen, or brittle

• Pressure remains high even after a thorough cleaning

• Water clarity issues persist despite chemical balance and cleanings

• The filter has gone uncleaned for several months and fails to recover after soaking and rinsing

Most filters last 3 to 5 years, depending on use, environmental factors, and how well they’re maintained. It’s a good idea to inspect the cartridge after each cleaning so you can catch early signs of wear before they affect your pool’s performance.

Steps to Proper Cartridge Filter Cleaning

1. Turn off your pump and relieve pressure on the system using the air relief valve.

2. Open the filter tank and carefully remove the cartridge elements.

3. Rinse thoroughly using a garden hose with a spray nozzle. Spray between the pleats from top to bottom.

4. Soak periodically in a filter cleaner solution (acid or degreaser-based, depending on buildup type) to break down oils and scale.

5. Rinse again thoroughly and inspect for wear or damage.

6. Reassemble the tank, re-pressurize, and turn the system back on.

Tip: Avoid using pressure washers—they can damage the pleats. And always wear gloves when using chemical cleaners.

A Word on Water Chemistry and Filter Efficiency

Water that’s out of balance—particularly with high calcium hardness or high pH—can cause scale to build up on your filter. Likewise, high oils or organics in the water can clog filters quickly.

Using an LSI-based water balance approach (as recommended by Orenda Technologies and endorsed by experts like Bob Lowry) helps minimize scale formation on filter elements.

Keeping water chemistry in check not only supports your pool's overall health—it also extends the life and performance of your cartridge filter.

Final Thoughts

Cleaning your cartridge filter isn’t just good practice—it’s essential for maintaining a healthy, beautiful swimming pool. A dirty or neglected filter can compromise everything else you do to keep your pool clean.

Regular cleaning improves water clarity, reduces chemical costs, and protects your investment in your pool equipment. Being proactive about when to clean and when to replace your filter helps prevent headaches down the road.

Whether you enjoy doing your own swimming pool cleaning or just want to understand how to care for your pool more effectively, staying on top of your cartridge filter maintenance is one of the best ways to ensure your Santa Rosa backyard retreat stays swim-ready all season long.

References:

• Pool & Hot Tub Alliance (PHTA) - www.phta.org

• Orenda Technologies - www.orendatech.com

• National Plasterers Council - www.nationalplastererscouncil.com

• Bob Lowry's Pool Chemistry Training Institute - www.poolchemistrytraininginstitute.com

• Swim University - www.swimuniversity.com

For more expert tips on swimming pool cleaning in Santa Rosa, check out our other blog posts or resources.