Pentair Sta-Rite System 3 Replacement Cartridge Pack S7M120 — Inner 100/Outer 200 (300 sq ft) OEM

Pentair Sta-Rite System 3 replacement cartridge pack (inner 100 sq ft + outer 200 sq ft) restores full 300 sq ft filtration for S7M120 modular media pool and spa filters.

Keep your Pentair Sta-Rite System 3 operating at peak performance with this genuine OEM cartridge set. The kit includes both the smaller inner cartridge (25021-0200S) and the larger outer cartridge (25022-0201S), engineered to match the S7M120 modular media filter’s specifications. Together they provide a combined 300 square feet of filter area, capturing dirt, pollen, and other fine particles to help maintain clearer pool and spa water while fitting the original housing without modification.

How do these cartridges fit my Sta-Rite System 3 S7M120?

These cartridges are made to the factory dimensions of the S7M120 modular media filter so replacement is straightforward. They slide into the filter housing in the same orientation as the originals and are supplied as a matched inner/outer set to ensure correct flow and coverage.

• Inner cartridge: 25-1/4" length × 8-1/2" diameter, 100 sq ft (part 25021-0200S)
• Outer cartridge: 18-1/2" length × 16-1/4" diameter, 200 sq ft (part 25022-0201S)
• Direct OEM fit for Pentair Sta-Rite System 3 S7M120

What filtration performance should I expect from this 300 sq ft pack?

With 300 square feet of combined filter media, the pack increases the surface area available for trapping suspended solids and debris compared with single-cartridge systems. Performance will depend on water conditions and maintenance, but the matched design helps preserve manufacturer-rated flow and filtration efficiency.

• High surface area reduces pressure rise and extends run times between cleanings
• Captures fine particles to improve water clarity
• Maintains designed flow rates for proper circulation when installed correctly

How do I maintain and clean these replacement cartridges?

Cleaning is simple and recommended on a regular schedule based on pool use and debris load. Remove the cartridges, rinse with a garden hose from top to bottom, and inspect for wear or torn media; replace the set when cleaning no longer restores performance.

• Rinse with low-pressure water; avoid high-pressure washers that can damage media
• Inspect end caps and seams for leaks or deterioration
• Replace both inner and outer cartridges together to preserve balanced filtration

Why choose genuine Pentair replacement cartridges instead of third-party alternatives?

OEM Pentair cartridges are manufactured to the original specifications for shape, media density, and sealing surfaces, helping ensure proper alignment within the S7M120 housing and predictable hydraulic characteristics. Using factory-approved parts reduces the risk of fit issues and helps preserve the filter’s designed performance.

• Includes official part numbers 25021-0200S (inner) and 25022-0201S (outer)
• Designed to match original flow and filtration characteristics
• Backed by Pentair's quality standards and compatibility testing

Who is this for? This cartridge pack is for pool and spa owners, maintenance professionals, and facility managers using Pentair Sta-Rite System 3 S7M120 modular media filters who want an exact-fit, high-capacity replacement. Choose this kit when you need to restore the filter’s full 300 sq ft of media area to regain longer run times, better water clarity, and trouble-free operation without modifying the filter housing.