Unicel 5CH-502 Replacement Filter for Marquis 03FIL0500 (new style) | 50 Sq. Ft.

Overview

The Unicel 5CH-502 is a pleated polyester spa cartridge filter element providing 50.0 sq ft of effective filtration area, engineered as a direct replacement for the Marquis 03FIL0500 (new style) housing configuration. Construction utilizes Reemay-grade nonwoven polyester media in a high-pleat-count configuration to maximize surface area within the spa-format envelope, with ABS injection-molded end caps configured for the threaded-handle mounting standard typical of the Marquis and Cal Spas cartridge platform. The element is rated for continuous service at spa operating temperatures up to 115°F with intermittent excursions to 120°F, and is dimensionally toleranced for bypass-free seating in compatible single-cartridge spa housings. Operating pressure range aligns with standard residential spa circulation systems in the 5–15 PSI envelope.

Service interval recommendation: rinse with fresh water every 2–4 weeks; chemical soak in dilute TSP or enzyme cleaner every 4–6 weeks to dissolve oils, lotions, and surfactant residue that resist mechanical rinsing. Replace at ≤ 12-month intervals under normal residential spa use, or sooner when ΔP rises ≥ 5 PSI above clean-filter baseline, when visual fabric degradation (tears, channeling, pleat collapse) is observed, or when chemical soak no longer restores baseline flow. Chemical compatibility: polyester media and ABS end caps tolerate continuous operation at ≤ 10 ppm free available chlorine or ≤ 30 ppm total bromine; muriatic acid soak at 1:20 dilution (20-minute maximum exposure) is approved for calcium scale removal, followed by thorough fresh-water rinse prior to reinstallation. Enzyme-based cartridge cleaners are compatible without restriction. Standard Unicel 90-day manufacturer's defect warranty applies through authorized distribution.

What's Included

Your order includes the selected quantity of replacement spa filter cartridges. Each unit is individually inspected for quality before shipping.