Sta-Rite Pool Filter Cartridges

Sta-Rite (a Pentair brand) makes the System:3 modular cartridge filter, which is genuinely unusual: it stacks two cartridge modules inside the tank rather than using one big element. That means you can replace just the top or bottom module if only one is failing, instead of a full cartridge replacement. That said, replacing both at once usually makes sense once you've drained the tank.

The 4 Sta-Rite systems below cover the System:3 configurations and their compatible cartridge modules.