Measure Your Old Hot Tub Filter
Use Menu to Narrow Your Search:
- Choose Type: Drop-In or Screw-In.
- Got Part #? [Search this category] No match? Go to 3.
- Pick: Spa Brand if known. No match? CLEAR Brand (x). Go to 4.
- Select: Diameter & Length ranges to narrow selection.
Follow measuring tips below:
![Measuring tips: tape measure showing fractional increments](https://cdn.shopify.com/s/files/1/0610/4370/3865/files/filter-measuring-756-04.jpg?v=1701556818)
Confirm Spa Filter Dimensions
- Round all figures to nearest ⅛”.
- Compare to search results.
- View photos to confirm match.
- Variances ±⅛” are normally OK.
See how to measure filter below:
![Measuring spa filter cartridge diameter & length](https://cdn.shopify.com/s/files/1/0610/4370/3865/files/filter-measuring-756-01.jpg?v=1701279980)
How-to Measure Diameter & Length
Measure old filter’s end-cap Diameter (edge-to-edge width) & Length (cap-to-cap height). Exclude handles/fittings.
![Measuring spa filter cartridge openings](https://cdn.shopify.com/s/files/1/0610/4370/3865/files/filter-measuring-756-02.jpg?v=1701280151)
How-to Measure Inner Opening
If filter has flush end-cap opening(s), measure Inside Diameter.
![Measuring spa filter cartridge fittings](https://cdn.shopify.com/s/files/1/0610/4370/3865/files/filter-measuring-756-03.jpg?v=1701280399)
How-to Measure External Fitting
If filter has a protruding fitting, measure Outside Diameter. Note style: Coarse Thread, Fine Thread, or Male Slip.