Search by entering your filter model number, any cartridge size, filter manufacturer name, cartridge number, or cartridge brand. You'll be able to refine your search in this column!
Browse Categories
Shopping Cart
Your cart is empty.
Measuring a Pool or Spa Filter Cartridge

The best way to find the correct replacement cartridge for your pool or spa is to follow these instructions for measuring (if you do not have the item number).

1. (A) Measure the outside diameter of the cartridge in inches (+/- 1/32") This is called the "Outer Diameter" or "OD"
2. (B) Measure from the top to the bottom of the cartridge length (+/- 1/32"), include the endcap measurement and DO INCLUDE THE HANDLE (if applicable). DO NOT inlcude the adapter if there is one. To be more accurate you should measure down the center of the unit from top to bottom.
3. (C) If your endcaps have an opening (most all do - some will have one end closed) measure the distance from the inside of the opening, this is called the "Inner Diameter" or "ID"
4. Check and see what kind of handle or end cap your existing cartridge has, match as closely as possible on the charts provided on the Spa Filter Cartridge and Pool Filter Cartridge pages.
5. As extra assurance you could count the pleats (+/-4) and note whether there is a center core or not.
6. Record the OEM name and model of the filter that the cartridge came out of, sometimes you can cross reference this name and number.

Below is a sample of a spa filter table and a pool cartridge table available on for your reference.

There is a Spa Filter Cartridge Table for each filter under each manufacturer along with a cross reference chart for Unicel, Pleatco and Filbur.

The Pool Filter Cartridge Table is available for each pool filter manufacturer along with the cross reference chart for Unicel, Pleatco and Filbur.