This is a package of Pentair 170146 Inner and Outer Cartridge Filter Elements for System 3 S7M400 Filters. It has a media area of 136 Square Feet for Inner Cartridge and 264 Square Feet for the Outer Cartridge. Cartridges are made of superior reinforced polyester pleated material with polyurethane end caps. Pentair reusable cartridge filter elements provide a high degree of water clarity and longer filter cycles. To maintain your pool water cleanliness and clarity, Pentair genuine replacement cartridge elements are the number one choice in cartridge filtration.
Pentair filter elements are designed to meet NSF's high quality performance and durability standards with Pentair filters. Only Pentair replacement filter cartridges will provide maximum hydraulic efficiency, exceptional first pass debris removal, and extended durability. This cartridge is individually packaged with the Pentair name on end caps and plastic wrap to identify as genuine Pentair parts.
The S7M120 and S7M400 models share a common 21" tank design, while the S8M150 and S8M500 models are equipped with a larger 25" tank. This shared tank architecture within each series creates a versatile system that allows for cartridge interchangeability.
Upgrade Options
Due to this compatibility, pool owners can upgrade or downgrade their filtration capacity as needed. For example, S7M120 owners seeking enhanced filtration or wanting to reduce filter maintenance frequency can upgrade to S7M400 cartridges. This upgrade provides a significant 33% increase in filtration capacity, expanding from 300 to 400 square feet of filter fabric area.
Downgrade Flexibility
Conversely, if you find your current filter system excessive for your pool's needs or wish to reduce cartridge costs, downgrades are equally possible. S7M400 owners can switch to S7M120 cartridges, while S8M500 users have the option to transition to S8M150 cartridges for more cost-effective maintenance.
D.E. Filter Compatibility
The System 3 D.E. cartridge models (S7MD60 and S7MD72) also offer interchangeable capabilities, both utilizing 21" tanks. This compatibility extends beyond just D.E. filters - a recent customer successfully converted their S7MD60 from D.E. filtration by replacing the D.E. cartridge with two S7M400 cartridges, demonstrating the versatility of the 21" tank shared across all S7M* series filters.
Pool Filter Purchase 
