Pleatco PFF25TC-P4 = Unicel 4CH-23 = Filbur FC-2400
25 sq ft hot tub filter, 4-5/8" diameter × 6-5/8" long. Top: Closed · Bottom: 1-1/2" MPT. Pleatco application: Freeflow Lagas, TLX, RLX.
Interchangeable cartridges
- Unicel 4CH-23 confirmed by: Pleatco p.47 (Unicel to Pleatco cross reference) Unicel p.8 (Cartridges by series (dimensional listing))
- Filbur FC-2400 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)
Check before you order
- Unicel 4CH-23 lists diameter 4-15/16" vs 4-5/8".
- Filbur FC-2400 lists diameter 4-15/16" vs 4-5/8".
Published dimensions, side by side
Each manufacturer measures a little differently. Compare these with your old cartridge.
| As published by | Pleatco PFF25TC-P4 source | Unicel 4CH-23 source | Filbur FC-2400 source |
|---|---|---|---|
| Outside diameter | 4-5/8" | 4-15/16" | 4-15/16" |
| Length | 6-5/8" | 6-5/8" | 6-5/8" |
| Top end | Closed | / closed | Closed |
| Bottom end | 1-1/2" MPT | / 1-1/2" male thread/MPT | 1-1/2" MPT |
| Filter area | 25 sq ft | 25 sq ft | 25 sq ft |
| Pleats | not listed | 212 | not listed |
| Media weight | 3 oz/yd² | 3 oz/yd² | not listed |
Where to buy
Search any retailer for 4CH-23 or PFF25TC-P4 or FC-2400. 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 |
|---|---|
FF-100 | Pleatco p.31: OEM part # column |
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.
- Freeflow Spas (models: CLX) Unicel p.35
FAQ
What is the Unicel equivalent of Pleatco PFF25TC-P4?
The catalogs cross-reference Pleatco PFF25TC-P4 to Unicel 4CH-23.
What is the Filbur equivalent of Pleatco PFF25TC-P4?
The catalogs list Filbur FC-2400.
What size is the PFF25TC-P4 filter?
Pleatco lists PFF25TC-P4 as 4-5/8" outside diameter by 6-5/8" long, top: Closed, bottom: 1-1/2" MPT, 25 sq ft.
Which OEM part numbers does it replace?
Listed OEM numbers: FF-100.
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.