Pleatco PSD125U = Unicel C-8325 = Filbur FC-2790
125 sq ft hot tub filter, 8-1/2" diameter × 17-3/4" long. Top: Multi-level Castle · Bottom: 2-3/4" beveled edge. Pleatco application: Sundance Horizontal Spa Cartridge.
Interchangeable cartridges
- Unicel C-8325 confirmed by: Pleatco p.47 (Unicel to Pleatco cross reference) Unicel p.20 (Cartridges by series (dimensional listing))Unicel note: Note: Length recorded is measured to first step. Replacement for 18" to 18-1/2" overall length.
- Filbur FC-2790 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
- Unicel C-8325 lists length 18" vs 17-3/4"; measure before ordering.
- Filbur FC-2790 lists length 18" vs 17-3/4"; measure before ordering.
Published dimensions, side by side
Each manufacturer measures a little differently. Compare these with your old cartridge.
| As published by | Pleatco PSD125U source | Unicel C-8325 source | Filbur FC-2790 source |
|---|---|---|---|
| Outside diameter | 8-1/2" | 8-7/16" | 8-1/2" |
| Length | 17-3/4" | 18" | 18" |
| Top end | Multi-level Castle | / closed w/ 3-step edge | Closed w/step |
| Bottom end | 2-3/4" beveled edge | 2-1/2" / open w/ beveled edge | 2-1/2" open |
| Filter area | 125 sq ft | 125 sq ft | 125 sq ft |
| Pleats | not listed | 201 | not listed |
| Media weight | 3 oz/yd² | 3 oz/yd² | not listed |
Where to buy
Search any retailer for C-8325 or PSD125U or FC-2790. 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 |
|---|---|
6540-490 | Pleatco p.35: OEM part # column Unicel p.59: OEM cross reference: Sundance 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.
- Sundance Spas (models: Universal Length; OEM 6540-490) Unicel p.59
FAQ
What is the Unicel equivalent of Pleatco PSD125U?
The catalogs cross-reference Pleatco PSD125U to Unicel C-8325.
What is the Filbur equivalent of Pleatco PSD125U?
The catalogs list Filbur FC-2790.
What size is the PSD125U filter?
Pleatco lists PSD125U as 8-1/2" outside diameter by 17-3/4" long, top: Multi-level Castle, bottom: 2-3/4" beveled edge, 125 sq ft.
Which OEM part numbers does it replace?
Listed OEM numbers: 6540-490.
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.