{"product_id":"pentair_25021-0224s","title":"Pentair Small Cartridge for the System 3 Filter S8M500 | 25021-0224S","description":"\u003cp\u003eThe Pentair Small Cartridge (25021-0224S) is the replacement 209 sq. ft. inner filtration module for the System 3 Modular Media Filter, model S8M500.\u003c\/p\u003e\n\u003cp\u003eThis cartridge module serves as the inner filtration media for the System 3 modular tank, using a shallow-pleat design that maximizes dirt-holding capacity within the modular tank housing. Because the media installs as a self-contained module, it can be replaced without disassembling or replacing the filter tank itself.\u003c\/p\u003e\n\u003cp\u003eThis is the smaller, inner cartridge for the S8M500.  For the matching larger, outer cartridge, see part number \u003cstrong\u003e\u003ca href=\"https:\/\/poolaroo.com\/products\/pentair_25022-0225s\"\u003e25022-0225S\u003c\/a\u003e\u003c\/strong\u003e.  Replace both to complete your filter service.\u003c\/p\u003e\n\u003cp\u003eFor a combo back of both filter cartridges, see the combo pack: \u003ca href=\"https:\/\/poolaroo.com\/products\/pentair_170148\"\u003e\u003cstrong\u003e170148\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; margin: 20px 0; border: 1px solid #ccc;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f8f9fa;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003ePentair Part Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e25021-0224S\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003ePart Name\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eSmall Cartridge\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f8f9fa;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003ePart Category\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eCartridges\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eQuantity Included\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eEach\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eFits Into\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; margin: 20px 0; border: 1px solid #ccc;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f8f9fa;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eEquipment Line\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eModel \/ Part Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e\u003cstrong\u003eNotes\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003ePentair\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eSystem 3\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003eS8M500\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e209 sq. ft. Inner Replacement Module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cem\u003eCompatibility is based on Pentair parts documentation and available OEM records. This is not an exhaustive list. For certainty, verify the part number in your equipment's manual or on the original part itself before ordering.\u003c\/em\u003e\u003c\/p\u003e\n\u003ch3\u003ePoolaroo Pro Tip\u003c\/h3\u003e\n\u003cp\u003eThe shallow-pleat design on this module is built for quick service — a hose-down is typically enough to clear routine debris buildup between full cleanings, helping maintain longer filter cycles on your System 3 filter.\u003c\/p\u003e\n\u003c!-- wft:processed:manual:2026-08-24 --\u003e","brand":"Pentair","offers":[{"title":"Default Title","offer_id":54309090459923,"sku":"25021-0224S","price":497.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0920\/0687\/5411\/files\/pentair-sta-rite-system-3-cartridge-filter-209-sf-25021-0224s-2.webp?v=1787612302","url":"https:\/\/poolaroo.com\/products\/pentair_25021-0224s","provider":"Poolaroo","version":"1.0","type":"link"}