PMAX50 / 5CH-35 / FC-0300
35 sq ft replacement filter cartridge • 5.75″ OD × 8.4375″ long
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PMAX50 replacements on Amazon
The buttons below pull up Amazon results for each cross-reference part number. Same physical cartridge, different stickers, often different prices. Cross-shop and pick the cheapest option that has solid recent reviews.
Frequently Asked Questions
What are the dimensions of the PMAX50?
The PMAX50 is 5.75 inches in outer diameter, 8.4375 inches long, with a handle top and a threaded bottom. Total filtration area is 35 square feet. Before ordering, pull your existing cartridge and measure it yourself, or check the label inside the housing. OD and length both have to match within about an eighth of an inch, and the end-cap style needs to match exactly so the cartridge seats properly when the lid closes.
What other part numbers are interchangeable with the PMAX50?
PMAX50 is the same physical cartridge as 5CH-35, FC-0300. Same dimensions (5.75" × 8.4375"), same handle top, same threaded bottom. The Pleatco, Unicel, and Filbur boxes ship the same media inside, just with different stickers. The only thing to watch is the end-cap style: if a cross-reference has a slightly different cap design, it may not seat right in your housing.
How often should I replace the PMAX50?
Most filter cartridges last between 12 and 24 months. Pull the PMAX50 every few months for a hose rinse, soak it in cleaner quarterly, and replace it when the pleats are torn, channeling, or won't come clean. Bather load, water chemistry, and how often you actually clean it all matter more than the calendar.
How do I clean the PMAX50?
The PMAX50 has a built-in handle on top, which means you can pull it without touching the media. Pull the cartridge from the housing and hose it down. Hit the pleats from above at about a 45-degree angle so water rinses debris out instead of packing it deeper, and work top to bottom while rotating the cartridge. Skip the pressure washer. The high pressure tears or collapses pleats, and once that happens you've lost media that doesn't come back. Every few months (or at every water change, whichever comes first), do a deep clean: overnight soak in a hot tub filter cleaner, then a thorough rinse. If your cartridge has a closed end cap, let it dry before reinstalling so you don't trap moisture inside the cartridge core.
Which hot tubs and spas use the PMAX50?
Pull your existing cartridge and read the part number off the end cap, or check the label inside the filter compartment. That's the most reliable way to confirm compatibility.
Dimensions
Specifications
| Outer Diameter | 5.75″ |
|---|---|
| Length | 8.4375″ |
| Top Type | Handle |
| Bottom Type | Threaded fitting |
| Filtration Area | 35 sq ft |
| Primary Brand | Pleatco |
| Part Number | PMAX50 |
Fitment notes
Semi-circular handle top with Pleatco's P4 adapter on the bottom, a 1-1/2 inch pipe thread. Pleatco lists the application as Maax Spas of Canada. Rated 35 sq ft despite the 50 in the part number, which both printings of the catalog agree on. The cross-reference needs care: Unicel's 5CH-35 is 5-5/8 by 8 inches and filed under Maax Elite Spas at OEM 104309, and Pleatco points its Artesian cartridge, the PAS35P, at the same 5CH-35 and FC-0300 while publishing a third set of dimensions. Treat both cross-references as nearest equivalents rather than exact matches. Pleatco also lists a PMAX50P4 at identical published dimensions, rating and bottom fitting.