PCST80 / C-5396 / FC-2975
100 sq ft replacement filter cartridge • 5.5625″ OD × 21.375″ long
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PCST80 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.
Cross-Reference & Interchangeable Part Numbers
| Brand | Part Number | Type |
|---|---|---|
| Pleatco | PCST80 | Primary |
| Unicel | C-5396 | Equivalent |
| Filbur | FC-2975 | Equivalent |
Always verify dimensions and end-cap type before purchasing a replacement.
Frequently Asked Questions
What are the dimensions of the PCST80?
The PCST80 is 5.5625 inches in outer diameter, 21.375 inches long, with an open top and an open bottom. Total filtration area is 100 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 PCST80?
PCST80 is the same physical cartridge as C-5396, FC-2975. Same dimensions (5.5625" × 21.375"), same open top, same open 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 PCST80?
Most filter cartridges last between 12 and 24 months. Pull the PCST80 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 PCST80?
The PCST80 has open ends on both top and bottom, so water flows straight through. 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 PCST80?
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 | 5.5625″ |
|---|---|
| Length | 21.375″ |
| Top Type | Open (no end cap) |
| Bottom Type | Open (no end cap) |
| Filtration Area | 100 sq ft |
| Primary Brand | Pleatco |
| Part Number | PCST80 |
Fitment notes
Open at both ends with roughly 2-1/8 inch openings, for Coast Spas and Waterway Plastics housings. Rated 100 sq ft by both sheets despite the 80 in the part number, so do not read the number as the filtration area. Unicel publishes its C-5396 as 5-5/16 by 21-5/16 inches against Pleatco's 5-9/16 by 21-3/8. The PCST120 is the same design in a 30 inch body. Note that PCST is Pleatco's Coast Spas prefix and has nothing to do with the PCS Coleman parts.