Pool Filter Source

Before ordering a replacement

How to measure a pool filter cartridge.

Use the old cartridge to confirm a likely replacement after searching the pool filter model or cartridge number.

Before removing the cartridge

Turn off the system and follow the manufacturer’s pressure-release instructions. Ask a pool professional if you’re unsure.

Tape measure across a pool filter cartridge end cap
Measure straight across the widest part of the end cap.

Picture guide

What to measure

Tape measure across a pool filter cartridge end cap01

Outside diameter

Measure straight across the widest part of the end cap. Don’t wrap the tape around it.

Tape measure running from end cap to end cap along a filter cartridge02

Cap-to-cap length

Measure the rigid cartridge body. Leave out handles and threaded stems unless a guide specifically asks for overall length.

Open and threaded filter cartridge end caps side by side03

Both end caps

Note open holes, closed caps, handles, threads, locking tabs, or a molded sealing ring.