Unicel 4CH-935 Replacement Filter for Waterway 500-0035L | 35 Sq. Ft.

Overview

The Unicel 4CH-935 is a pleated polyester spa cartridge filter element providing 35.0 sq ft of effective filtration area through a Reemay nonwoven polyester media pack with nominal 15-micron filtration efficiency. Dimensional specifications: 4.875-inch OD, 2.0-inch ID with 1.5-inch threaded SAE bottom hub, 9.25-inch overall length; end cap configuration features an ABS-molded threaded bottom (1.5-inch MPT integrated handle) and a closed top cap. The element is supplied in coreless construction, with pleat geometry providing axial stability across the spa pressure operating range (5–15 PSI typical). Continuous service temperature is rated to 104°F with intermittent excursions to 120°F per manufacturer testing. The threaded-handle bottom interface eliminates separate retention hardware and enables single-cartridge tool-free service in skim-filter housing configurations.

Service interval recommendation: spa applications — rinse with fresh water every 2–4 weeks; chemical soak (TSP solution or dedicated enzyme cartridge cleaner) every 4–6 weeks to remove body oils, lotions, and surfactant residue that resist rinse-only cleaning. Replacement is recommended at 12-month maximum service life, or at ΔP ≥ 5 PSI above clean operating baseline, whichever occurs first. Chemical compatibility: polyester media and ABS end caps tolerate continuous service at ≤ 10 ppm free available chlorine or ≤ 30 ppm total bromine; muriatic acid soak at 1:20 dilution compatible for calcium scale removal (20-minute maximum exposure, thorough rinse before reinstallation). Avoid ozone-primary sanitization exposure without verifying media compatibility. Standard Unicel 90-day manufacturer's defect warranty applies through authorized distribution.

What's Included

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