The USWF 5 Micron 20x4.5 String Wound Sediment Filter has a nominal filtration rating of 5 microns, making it highly effective at reducing sand, silt, rust flakes, scale particles, and other fine sediment from your water supply. The tightly wound polypropylene string construction creates a true depth-filtration media that traps particles throughout the entire thickness of the cartridge, not just on the surface, providing superior dirt-holding capacity compared to standard spun or pleated filters of similar size.

This USWF cartridge measures 20 inches in length by 4.5 inches in outer diameter (Big Blue size), with a standard 1-inch inner core diameter. It is designed as a direct fit for all standard 20" x 4.5" Big Blue whole-house filter housings, including Pentek, Pentair, American Plumber, and other compatible 20-inch heavy-duty housings. It is ideal for high-flow whole-house applications, well water pre-filtration, and point-of-entry systems requiring robust sediment removal.

The USWF 5 Micron 20x4.5 String Wound Sediment Filter typically lasts 3 to 6 months under normal household water conditions, or approximately when pressure drop becomes noticeable. Actual life depends heavily on your incoming water quality—homes on well water or with high sediment loads may need replacement every 1–3 months, while municipal water users often get the full 6 months. Monitor the cartridge visually; when it appears heavily discolored or flow rate drops, it is time to replace.

The USWF 5 Micron 20x4.5 String Wound Sediment Filter is constructed from 100% FDA-compliant food-grade polypropylene string tightly wound around a polypropylene center core. The materials meet NSF/ANSI Standard 42 requirements for material safety in drinking water applications. The all-polypropylene construction contains no binders, adhesives, resins, or surfactants, making it chemically compatible with a wide pH range (1–13) and suitable for potable water, as well as chemical and industrial pre-filtration applications.

Yes, the USWF 5 Micron 20x4.5 String Wound Sediment Filter is an excellent choice for well water pre-filtration, effectively capturing iron particulates, sand, and silt that commonly foul downstream equipment like softeners, UV systems, and RO units. It also has a high temperature tolerance of up to 165°F (74°C), making it suitable for hot water line applications where most pleated or spun polypropylene filters would deform. Operating pressure range is 20–100 psi with a maximum differential pressure of 35 psi before replacement is required.