{"product_id":"pentair_25021-0200s","title":"Pentair Small Cartridge for System 3 Filters | 25021-0200S","description":"\u003cp\u003eThe Pentair Small Cartridge (25021-0200S) is the OEM replacement 100 sq. ft. inner filter module for the Sta-Rite System 3 Modular Media Filter, model S7M120.\u003c\/p\u003e\n\u003cp\u003eThis module is the internal filtration media component of the System 3 modular media filter system. It installs inside the existing System 3 tank housing, allowing the filter media to be serviced or replaced without removing or replacing the outer tank shell.\u003c\/p\u003e\n\u003cp\u003eThis is the smaller, inner cartridge for the S7M120.  For the matching larger, outer cartridge, see part number \u003ca href=\"https:\/\/poolaroo.com\/products\/pentair_25022-0201s\"\u003e\u003cstrong\u003e25022-0201S\u003c\/strong\u003e\u003c\/a\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_170145\"\u003e\u003cstrong\u003e170145\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;\"\u003e25021-0200S\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: white;\"\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: white;\"\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: white;\"\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003ePentair (formerly Sta-Rite)\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;\"\u003eS7M120\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ccc; padding: 10px;\"\u003e100 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\u003eBecause this module drops into the existing System 3 tank shell, replacing it doesn't require any plumbing changes to the tank itself. Rinse the media module regularly and inspect the tank o-ring seal at the same time to help maintain consistent flow between filter cycles.\u003c\/p\u003e\n\u003c!-- wft:processed:manual:2026-08-24 --\u003e","brand":"Pentair","offers":[{"title":"Default Title","offer_id":54309090165011,"sku":"25021-0200S","price":196.88,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0920\/0687\/5411\/files\/pentair-large-cartridge-for-the-system-3-s7m120-filter-25022-0201s.webp?v=1787611376","url":"https:\/\/poolaroo.com\/products\/pentair_25021-0200s","provider":"Poolaroo","version":"1.0","type":"link"}