Unicel C-2303 Replacement Filter for Rainbow R173324 | 8.5 Sq. Ft.

Overview

The Unicel C-2303 is a pleated polyester spa cartridge filter element providing 8.5 sq ft of filtration area in a compact form factor engineered for residential spa and portable hot tub circulation systems. Dimensional specifications: 4.25-inch OD, 2.125-inch ID, 4.875-inch length, with a top handle / bottom SAE thread end cap configuration typical of the Rainbow/Pentair Dynamic series spa filter family. End cap construction is ABS injection-molded with chemically bonded adhesive rated for continuous spa-temperature service to 104°F. Media specification: Reemay nonwoven polyester, nominal 20-micron filtration efficiency, supported on a perforated polypropylene core for axial rigidity under cyclic pump loading. Operating pressure range: 5–15 PSI typical for spa circulation; maximum rated working pressure 25 PSI.

Service interval recommendation: rinse with fresh water every 2–4 weeks; chemical soak in dilute TSP or commercial filter cleaner every 4–6 weeks to remove body oils, surfactants, and lotion residues that resist rinse-only cleaning. Replacement cycle: 12–15 months under normal residential bather load, or upon ΔP rise of ≥ 5 PSI above clean-filter baseline, whichever occurs first. Chemical compatibility: polyester media tolerates continuous service at ≤ 10 ppm free chlorine or ≤ 30 ppm total bromine; muriatic acid soak at 1:20 dilution is compatible with the ABS end cap construction for calcium scale removal (20-minute maximum exposure, thorough rinse before reinstallation). Enzyme cleaner compatible without restriction. Standard Unicel 90-day manufacturing 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.