Product Overview

Replace the large outer cartridge in your Sta-Rite System:3 S8M500 modular media filter with genuine Pentair part 25022-0225S. This replacement module provides 291 sq. ft. of filtration area and surrounds the smaller inner cartridge inside the S8M500 tank.

The S8M500 uses two separate elements: a 291 sq. ft. outer cartridge and a 209 sq. ft. inner cartridge. Together, they provide the filter’s 500 sq. ft. of filtration area. This listing is for the outer cartridge only, allowing you to replace it individually when its media or structure is damaged or cleaning no longer restores satisfactory performance.

Key Features

• Genuine Pentair / Sta-Rite replacement cartridge
• 291 sq. ft. outer filter module
• Designed for the System:3 S8M500
• Replaces the large cartridge surrounding the inner element
• Sold individually; inner cartridge is separate
• Manufacturer part number 25022-0225S

Compatibility & Specifications

Confirm “S8M500” on the filter’s model label before ordering. The S7M400 uses outer cartridge 25022-0224S and inner cartridge 25021-0223S. Its elements are different sizes from those used in the S8M500.

Cleaning & Replacement

Turn off the pump and fully release filter pressure before opening the tank. Remove and inspect both cartridges according to the System:3 filter instructions. Replace the outer element if its pleats, end caps, or structure are damaged, or if proper cleaning no longer restores acceptable filtration.

Before reassembly, inspect the inner cartridge, tank seal, and clamp components. Seat the cartridges correctly, secure the tank as directed, and release trapped air during startup. If both S8M500 elements need replacement, order this outer cartridge along with inner cartridge 25021-0224S.

Frequently Asked Questions

Is this the inner or outer S8M500 cartridge?
It is the 291 sq. ft. outer cartridge.

Does this include the 209 sq. ft. inner cartridge?
No. The inner cartridge, 25021-0224S, is sold separately.

Will it fit an S7M400 filter?
No. The S7M400 outer cartridge is 25022-0224S.

Is this a complete filter assembly?
No. It is one replacement cartridge for an existing S8M500 filter.