Pleatco PCD100W = Unicel C-8399 = Filbur FC-3965
100 sq ft hot tub filter, 8" diameter × 16-1/2" long. Top: Handle · Bottom: 3-5/8" open. Pleatco application: Caldera 100.
Interchangeable cartridges
- Unicel C-8399 confirmed by: Pleatco p.47 (Unicel to Pleatco cross reference) Unicel p.20 (Cartridges by series (dimensional listing))
- Filbur FC-3965 confirmed by: Pleatco p.48 (Filbur to Pleatco cross reference) Filbur p.33 (Reverse cross reference (Unicel to Filbur)) Filbur p.12 (Dimensional cartridge listing)
Check before you order
- Filbur FC-3965 lists bottom opening 3-1/2" open vs 3-5/8" open.
Published dimensions, side by side
Each manufacturer measures a little differently. Compare these with your old cartridge.
| As published by | Pleatco PCD100W source | Unicel C-8399 source | Filbur FC-3965 source |
|---|---|---|---|
| Outside diameter | 8" | 8" | 8" |
| Length | 16-1/2" | 16-1/2" | 16-1/2" |
| Top end | Handle | / semi-circular handle | Handle |
| Bottom end | 3-5/8" open | 3-5/8" / open w/ lip seal | 3-1/2" open |
| Filter area | 100 sq ft | 100 sq ft | 100 sq ft |
| Pleats | not listed | 259 | not listed |
| Media weight | 3 oz/yd² | 3 oz/yd² | not listed |
Where to buy
Search any retailer for C-8399 or PCD100W or FC-3965. These are the same cartridge under different brand names.
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OEM part numbers this cartridge replaces
As printed in the cited aftermarket catalogs. Match the number on your old cartridge or in your spa manual exactly.
| OEM number | Listed in |
|---|---|
1039607 | Pleatco p.35: OEM part # column Unicel p.30: OEM cross reference: Caldera Spas |
73722 | Unicel p.30: OEM cross reference: Caldera Spas |
Hot tub brands that use it
From the spa-manufacturer cross reference in the Unicel 2026 Replacement Guide. A brand may use several sizes, so check your measurements.
- Caldera Spas (OEM 1039607, 73722) Unicel p.30
FAQ
What is the Unicel equivalent of Pleatco PCD100W?
The catalogs cross-reference Pleatco PCD100W to Unicel C-8399.
What is the Filbur equivalent of Pleatco PCD100W?
The catalogs list Filbur FC-3965.
What size is the PCD100W filter?
Pleatco lists PCD100W as 8" outside diameter by 16-1/2" long, top: Handle, bottom: 3-5/8" open, 100 sq ft.
Which OEM part numbers does it replace?
Listed OEM numbers: 1039607, 73722.
Sources: Filbur Product Catalog and Reference Guide (2024) · Filbur Product Catalog and Reference Guide (2024) · Pleatco 2023 Catalog & Cross Reference Guide (Pentair) · Pleatco 2023 Catalog & Cross Reference Guide (Pentair) · Pleatco 2023 Catalog & Cross Reference Guide (Pentair) · Unicel 2026 Replacement Guide. Last checked 2026-10-21.