About FilterHound
FilterHound exists because I got tired of the same pattern every time a filter needed replacing: pull the cartridge, squint at the half-faded part number, and then spend twenty minutes piecing together which Pleatco, Unicel, Filbur, and OEM numbers all referred to the same physical cartridge.
The information was out there, just scattered across PDF catalogs, forum threads, and the back-of-package label of whatever brand the last owner happened to grab off the shelf. So I started compiling it for myself. This site is what came out of that!
Who's behind this
I'm Aaron Ford, the person who built and maintains FilterHound. The site's named after my actual dog. Felix, the cartoon hound you see around the site, is loosely based on him.
I'm not a pool tech or a manufacturer rep. I'm just a software engineer who owns a hot tub and got curious about why filter cross-referencing was so painful. That's the level of expertise you should expect from this site: careful research, structured data, and honest sourcing. Not field experience.
How the data is sourced
Cross-reference data comes from public manufacturer catalogs (Pleatco, Unicel, and Filbur all publish theirs), spa and pool OEM service documents, and verification against multiple sources where catalogs conflict. When two sources disagree about which cartridge fits a specific spa model, I tend to defer to the spa manufacturer over the filter manufacturer.
The site doesn't guess. If a model isn't in our list, that means I haven't verified its filter spec, not that it's incompatible with everything. Spec data is dimensions, square footage, and end-cap type. None of those are subjective.
What you'll find here
- Cartridge cross-references between Pleatco, Unicel, and Filbur
- OEM equivalents from Jacuzzi, Hot Spring, Caldera, and others
- Dimensions, square footage, and end-cap configuration for each cartridge
- Compatible spa and pool models, both directions
- Browse-by-size pages for when you have a measuring tape but no part number
- Direct links to Amazon listings
About the Amazon links
The Amazon links on this site are affiliate links. If you buy a cartridge through one of them, I get a small commission from Amazon (you pay the same price). That's how the site stays free. The full disclosure is here.
The presence of an Amazon link doesn't mean a brand sponsored inclusion. Cartridge data and Amazon links are independent: the data is what it is, and the affiliate link goes to whatever generic Amazon search returns the part number you searched for.
Found something wrong?
If you think a cross-reference is off, a model is missing, or a spec looks wrong on the page, tell me about it. Specific details help: the part number, the spa or pool model, and where you saw the correct info. The contact form is here.