Unicel C-8409 90 Sq Ft Replacement Pool Filter Cartridge - Reliable

In this review the Unicel C-8409 cartridge is evaluated for homeowners and pool maintainers who need a straightforward, effective replacement filter. The bottom line: this cartridge delivers reliable debris removal thanks to its 90 square feet of media and 174 pleats, making it a practical choice for owners of compatible Hayward, Sta-Rite, and Waterway systems who want clear water without specialty parts. It stands out for ease of installation and durable materials rather than high-end performance claims.

Key Features

• Filtration area: 90 square feet of media provides substantial surface to trap dirt and debris for longer intervals between cleanings.
• Pleat design: 174 sharp, uniform pleats maximize usable surface area so the cartridge holds more debris while maintaining good flow.
• Particle capture: 4-ounce basis weight media captures particles down to an average of 20 microns, helping maintain clearer pool water.
• Material construction: 100-percent polyester Reemay media balances dirt-holding capacity and cleanability with strong chemical resistance for longer life.
• End cap and fit: A 4-in ID open end cap with molded gasket and durable plastic resists chemical damage and allows straightforward removal and replacement.
• Compatibility: Size and design make it compatible with common Hayward, Sta-Rite, and Waterway setups, reducing fit concerns for many owners.

Who It's For

The Unicel C-8409 is best for residential pool owners who use cartridge-style filters from Hayward, Sta-Rite, or Waterway and want a dependable, easy-to-clean replacement that balances performance and cost. It suits people who perform regular maintenance and prefer a cartridge they can rinse and reuse rather than a disposable option.

It is less appropriate for owners seeking ultra-fine filtration below 20 microns or commercial installations that require specialty media or very high flow rates; those buyers should consider dedicated commercial cartridges or alternative media designed for finer filtration or heavy industrial use.

Pros & Cons

Pros

• Good value for the size and material, offering 90 sq ft of effective filtration surface.
• Durable polyester Reemay media resists chemicals and rinses clean for repeated use.
• Well-shaped pleats maintain flow and increase dirt-holding capacity compared with flat media.
• End cap with molded gasket and common 4-in ID makes installation and removal simple.

Cons

• Average particle capture is about 20 microns, so it may not meet needs where ultra-fine filtration is required.
• Not a proprietary high-end media; performance depends on regular cleaning to maintain effectiveness.

Specifications

Model	C-8409
Filtration area	90 sq ft
Pleats	174 pleats
Media	100% polyester Reemay, 4-oz basis weight
Particle capture	Average 20 microns
Outer diameter	8-15/16 in
Length	17-3/8 in
End cap	4-in ID open configuration with molded gasket

Our Verdict

The Unicel C-8409 is a practical, value-oriented replacement cartridge for typical residential cartridge filter systems. It combines generous media area, durable polyester construction, and an easy-fit end cap to deliver effective debris removal and straightforward maintenance, making it a sensible buy for pool owners who clean cartridges regularly and want reliable performance without specialty pricing.

Frequently Asked Questions

Will this cartridge fit my Hayward filter?
It is designed to be compatible with many Hayward, Sta-Rite, and Waterway cartridge systems; check that your filter accepts a cartridge with an 8-15/16 in OD, 17-3/8 in length, and 4-in ID end cap.

How often should I clean this cartridge?
Cleaning frequency depends on pool use and debris levels, but owners commonly rinse and vacuum the cartridge monthly during peak season and more often if pressure rises quickly.

Can the cartridge be reused after cleaning?
Yes; the 100% polyester Reemay media is designed for repeated rinsing and cleaning while retaining chemical resistance and durability.