SpiroPure Spa Filter Cartridge replacement for Pleatco PWW50L / Unicel 4CH-949 — 5" x 13" trilobal media, reinforced end caps

SpiroPure Replacement for Pleatco PWW50L Unicel 4CH-949 FC-0172 is a direct-fit spa filter cartridge engineered to restore clear, debris-free water in compatible Cal Spa systems.

Designed as a high-quality alternative to factory parts, this SpiroPure cartridge uses trilobal filtration media and reinforced end caps to remove hair, sand, and fine debris while resisting routine chemical exposure. It matches common OEM dimensions and threads so you can swap it into many hot tub and pool filter housings without extra adapters. Read on for what it fits, how it performs, and simple installation and maintenance tips.

Will this filter fit my spa or hot tub?

This cartridge is built to match the popular OEM sizes used in many Cal Spa systems and other brands. Before ordering, verify your current filter’s outer diameter, length, and thread type to ensure correct fit.

• Outer diameter: 5 inches
• Length: 13 1/16 inches
• Thread: 1.5 inch female coarse (SAE)
• Compatible OEMs: Pleatco PWW50L, Unicel 4CH-949, Filbur FC-0172

How does the filtration material help maintain water clarity?

The SpiroPure cartridge uses trilobal synthetic media that increases surface area and traps smaller particles more effectively than standard flat fibers. This improves debris capture while maintaining flow, so pumps don’t have to work harder to move water through the system.

• Trilobal fibers capture fine dirt, hair, and sand
• Layered pleats preserve flow while increasing filter area
• Helps reduce visible debris and prolongs water clarity

How durable is the SpiroPure replacement compared to OEM filters?

SpiroPure emphasizes reinforced construction to withstand typical spa chemicals and repeated cleaning cycles. Molded high-strength end caps and durable media help the cartridge retain shape and performance across multiple maintenance intervals.

• High-strength molded end caps resist cracking
• Media engineered for repeated rinsing and light chemical exposure
• Manufactured to hold pleat spacing and integrity over time

What are easy maintenance tips for getting the most life from this filter?

Regular rinse-cleaning and periodic deep-soak cleans extend filter life and keep flow efficient. Avoid harsh tools or wire brushes that can damage the pleats; handle the cartridge gently when removing and reinstalling.

• Rinse weekly with a garden hose after removing debris
• Soak monthly in filter cleaner for deep residue removal
• Inspect seals and threads for wear before reinstalling

Who is this for: The SpiroPure replacement cartridge is intended for hot tub and small pool owners, service technicians, and retailers seeking a reliable, cost-effective substitute for Pleatco PWW50L, Unicel 4CH-949, or Filbur FC-0172 filters. It suits anyone who needs an exact-dimension cartridge with a durable end cap and improved particulate capture—especially users of compatible Cal Spa models (FIL50-5D13H15FCT, FIL11100208). If you’re replacing a worn or clogged filter and want to maintain water clarity and pump efficiency without modifying your equipment, this SpiroPure cartridge is a direct-fit option to consider.