Pleatco PMT50 = Unicel C-4305 = Filbur FC-1630 = Filbur FC-1617
50 sq ft hot tub filter, 5" diameter × 14-3/4" long. Top: 2-1/8" open · Bottom: 2-1/8" open. Pleatco application: Sonfarrel 50-220152, Cal Spas, Martec, Advantage Mfg..
Interchangeable cartridges
- Unicel C-4305 confirmed by: Pleatco p.47 (Unicel to Pleatco cross reference) Unicel p.9 (Cartridges by series (dimensional listing))
- Filbur FC-1630 confirmed by: Pleatco p.48 (Filbur to Pleatco cross reference) Filbur p.33 (Reverse cross reference (Unicel to Filbur)) Filbur p.9 (Dimensional cartridge listing)
- Filbur FC-1617 confirmed by: Filbur p.33 (Reverse cross reference (Unicel to Filbur)) Filbur p.9 (Dimensional cartridge listing)
Check before you order
- Listed by Filbur's reverse cross reference only; Pleatco maps this cartridge to a different Filbur number.
Published dimensions, side by side
Each manufacturer measures a little differently. Compare these with your old cartridge.
| As published by | Pleatco PMT50 source | Unicel C-4305 source | Filbur FC-1630 source |
|---|---|---|---|
| Outside diameter | 5" | 4-15/16" | 4-15/16" |
| Length | 14-3/4" | 14-7/8" | 14-7/8" |
| Top end | 2-1/8" open | 2-1/8" / open | 2-1/8" open |
| Bottom end | 2-1/8" open | 2-1/8" / open | 2-1/8" open |
| Filter area | 50 sq ft | 50 sq ft | 50 sq ft |
| Pleats | not listed | 193 | not listed |
| Media weight | 3 oz/yd² | 3 oz/yd² | not listed |
Where to buy
Search any retailer for C-4305 or PMT50 or FC-1630 or FC-1617. 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.
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.
- Advantage Mfg. Unicel p.26
- Cal Spas Unicel p.30
- Dolphin Spas Unicel p.34
- Martec (OEM CL-2807) Unicel p.44
- Pageant Spas Unicel p.46
- Sonfarrel (OEM 220142, 220145, 220175) Unicel p.56
- Sundance Spas (OEM 6540-497) Unicel p.59
FAQ
What is the Unicel equivalent of Pleatco PMT50?
The catalogs cross-reference Pleatco PMT50 to Unicel C-4305.
What is the Filbur equivalent of Pleatco PMT50?
The catalogs list Filbur FC-1630, FC-1617.
What size is the PMT50 filter?
Pleatco lists PMT50 as 5" outside diameter by 14-3/4" long, top: 2-1/8" open, bottom: 2-1/8" open, 50 sq ft.
Which OEM part numbers does it replace?
Listed OEM numbers: CL-2807, CL2810, 220142, 220145, 220175, 6540-497.
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.