PCD100W / C-8399 / FC-3965
100 sq ft replacement filter cartridge • 8″ OD × 16.5″ long
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Use the part-number links below to compare compatible cartridges. Prices and availability vary, so verify dimensions before ordering.
Cross-Reference & Interchangeable Part Numbers
| Brand | Part Number | Type |
|---|---|---|
| Pleatco | PCD100W | Primary |
| Unicel | C-8399 | Equivalent |
| Filbur | FC-3965 | Equivalent |
| OEM | Caldera 73722 | Original Equipment |
| OEM | Caldera 1039607 | Original Equipment |
| OEM | Caldera 81004 | Original Equipment |
Always verify dimensions and end-cap type before purchasing a replacement.
Compatible Hot Tubs & Spas
The following spa models use the PCD100W (or an interchangeable equivalent). Always confirm with your owner's manual.
Frequently Asked Questions
What are the dimensions of the PCD100W?
The PCD100W measures 8 inches in outer diameter and 16.5 inches in length, with a handle top and open bottom. It provides 100 square feet of filtration area. Always measure your existing cartridge or check the label inside the filter housing before ordering - outer diameter and length are the two critical dimensions, but end-cap style must also match.
What other part numbers are interchangeable with the PCD100W?
The PCD100W is interchangeable with C-8399, FC-3965, and OEM equivalents including Caldera 73722, Caldera 1039607, Caldera 81004. All of these share the same 8" OD × 16.5" dimensions and handle top / open bottom end caps. When buying a cross-reference, confirm the end-cap style matches - a small difference in cap design can prevent proper seating in your filter housing.
How often should I replace a PCD100W filter cartridge?
At 100 sq ft, the PCD100W has plenty of filtration area for the volume of water in most hot tubs. Under typical residential use (2-4 people, 2-3 times per week), most owners replace it every 18-24 months. Monthly rinsing and a quarterly overnight soak in filter cleaner will keep it flowing freely and extend its life.
How do I clean a PCD100W filter cartridge?
The PCD100W has a handle on top, making it easier to lift out of the housing without touching the filter media. Remove the cartridge from its housing and rinse thoroughly with a garden hose, directing the stream at a 45-degree angle between the pleats - work from top to bottom, rotating around the cartridge. Avoid pressure washers, which collapse the pleats and permanently reduce filtration efficiency. For a deeper clean every 3-4 months, soak overnight in a hot tub filter cleaner solution, then rinse thoroughly. Never reinstall a wet cartridge if you're using a cartridge with a closed end - let it dry to prevent trapping moisture inside.
Which hot tubs and spas use the PCD100W filter?
The PCD100W is compatible with the following models: Caldera Geneva, Caldera Niagara, Caldera Utopia, Caldera Vacanza, Caldera Salina, Caldera Marino. Always cross-check your spa's owner manual or the label inside the filter compartment to confirm the correct part number.
Dimensions
Specifications
| Outer Diameter | 8″ |
|---|---|
| Length | 16.5″ |
| Top Type | Handle |
| Bottom Type | Open (no end cap) |
| Filtration Area | 100 sq ft |
| Primary Brand | Pleatco |
| Part Number | PCD100W |