Product Overview

Replace the large outer cartridge in your Sta-Rite System:3 S7M400 filter with genuine Pentair part 25022-0224S. This module provides 264 sq. ft. of filtration area and fits around the smaller inner cartridge inside the filter tank.

The S7M400 uses two cartridges that work together: this 264 sq. ft. outer module and a 136 sq. ft. inner module. Their combined area is 400 sq. ft. Because the cartridges are available separately, you can replace the outer element when it is damaged or worn without automatically replacing a serviceable inner element.

Key Features

• Genuine Pentair / Sta-Rite replacement cartridge
• 264 sq. ft. outer filter module
• Designed for the System:3 S7M400
• Replaces the large cartridge surrounding the inner element
• Sold individually; inner cartridge is separate
• Manufacturer part number 25022-0224S

Compatibility & Specifications

Check the model label before ordering. This cartridge is for the S7M400. The larger S8M500 uses outer cartridge 25022-0225S; the two outer modules should not be treated as interchangeable.

Cleaning & Replacement

Turn off the pump and fully release pressure through the filter’s air relief valve before opening the tank. Remove the existing cartridges according to the System:3 instructions. Inspect the outer element for torn pleats, damaged end caps, or structural wear. If thorough cleaning no longer restores acceptable filter performance, replacement may be appropriate.

While the filter is open, inspect the inner cartridge, tank seal, clamps, and sealing surfaces. Seat both elements properly during reassembly, secure the tank according to Pentair’s instructions, and release trapped air at startup. If both S7M400 cartridges need replacement, order this outer module together with inner module 25021-0223S.

Frequently Asked Questions

Is 25022-0224S the inner or outer cartridge?
It is the 264 sq. ft. outer cartridge for the S7M400.

Does it include the inner cartridge?
No. The 136 sq. ft. inner cartridge, part 25021-0223S, is sold separately.

Will it fit an S8M500 filter?
No. The S8M500 uses outer cartridge 25022-0225S.

Do both cartridges need replacement at the same time?
Inspect and clean both cartridges. Replace each based on its condition.