Pentair S7M400 Sta-Rite System 3 Large Outer Cartridge Filter 264 sf 25022-0224S

This cartridge is designed for homeowners running the Sta-Rite System 3 Modular Media 400 filter, one of Pentair’s high-capacity cartridge systems. Because the filter uses two cartridges—an outer 264 sq ft element and an inner 136 sq ft element—this outer cartridge handles the bulk of debris capture and helps maintain strong flow rates.

The large filtration area makes it especially effective for medium to large residential pools where high circulation and debris capture are important. Pool owners often choose System 3 filters because they provide DE-like clarity without backwashing, and replacing worn cartridges restores that performance quickly. With proper cleaning and care, these cartridges can deliver several seasons of reliable filtration.

Best for:
Sta-Rite System 3 S7M400 filters
Medium-to-large residential pools
Pools needing high debris-holding capacity

Not ideal for:
Clean & Clear or other Pentair cartridge systems
DE or sand filters
System 3 models other than S7M400