{"product_id":"unicel-c-4301","title":"Unicel C-4301 Replacement Filter for Sonfarrel 220122 | 27.5 Sq. Ft.","description":"\u003cdiv class=\"pz-pdp\"\u003e\n\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThe Unicel C-4301 is a pleated polyester spa cartridge filter element providing 27.5 sq ft of filtration area in a compact form factor engineered for Sonfarrel-pattern housings. Dimensional specifications: 4.9375-inch OD, 2.0625-inch ID with a closed top end cap, and 6.625-inch overall length. Media construction utilizes Reemay-grade nonwoven polyester fabric at a nominal 15-micron filtration efficiency, mounted on an open-flow bottom end cap and supported by a perforated PVC core for axial rigidity under standard spa operating pressures (5–15 PSI). End caps are ABS injection-molded with chemical-resistant bond adhesive, rated for continuous service to 104°F and intermittent excursions to 115°F. The high pleat density delivers substantial dirt-holding capacity within a short element profile, well-suited to high-turnover, low-clearance filter canisters.\u003c\/p\u003e\n\u003cp\u003eService interval recommendation: rinse with fresh water every 2–4 weeks; perform chemical soak (dilute TSP or commercial enzyme cleaner) every 4–6 weeks to remove accumulated oils, lotions, and surfactants that resist standard rinse procedures. Replace the element at ΔP ≥ 5 PSI above clean operating baseline, or on a 12-month calendar cycle, whichever occurs first; spas under continuous bather load should anticipate accelerated replacement intervals. 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 is compatible for calcium scale removal (20-minute maximum exposure, thorough rinse required); enzyme cleaners are compatible without restriction. Standard Unicel 90-day manufacturer's defect warranty applies through authorized distribution.\u003c\/p\u003e\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cp\u003eYour order includes the selected quantity of replacement pool filter cartridges. Each unit is individually inspected for quality before shipping.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Unicel","offers":[{"title":"Default Title","offer_id":42315911004206,"sku":"UNFC4301","price":33.21,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0016\/3453\/3422\/files\/UNFC4301_c78a7373-7953-43f1-85c2-527105e39c27.jpg?v=1777663103","url":"https:\/\/poolzilla.com\/products\/unicel-c-4301","provider":"Poolzilla","version":"1.0","type":"link"}