Pleatco PFF42TC-P4 = Unicel 5CH-37 = Filbur FC-2402
42 sq ft hot tub filter, 5-1/4" diameter × 9-3/8" long. Top: Closed - String Handle · Bottom: 1-1/2" MPT. Pleatco application: Freeflow 2013 - current.
Interchangeable cartridges
- Unicel 5CH-37 confirmed by: Pleatco p.47 (Unicel to Pleatco cross reference) Unicel p.11 (Cartridges by series (dimensional listing))Unicel note: Note: Original has a closed top w/ string handle.
- Filbur FC-2402 confirmed by: Pleatco p.48 (Filbur to Pleatco cross reference) Filbur p.10 (Dimensional cartridge listing)
Check before you order
- Unicel 5CH-37 lists length 9" vs 9-3/8"; measure before ordering.
- Unicel 5CH-37 rates it 37.5 sq ft (vs 42 sq ft); filter area ratings differ by maker.
- Filbur FC-2402 rates it 40 sq ft (vs 42 sq ft); filter area ratings differ by maker.
Published dimensions, side by side
Each manufacturer measures a little differently. Compare these with your old cartridge.
| As published by | Pleatco PFF42TC-P4 source | Unicel 5CH-37 source | Filbur FC-2402 source |
|---|---|---|---|
| Outside diameter | 5-1/4" | 5-5/16" | 5-3/8" |
| Length | 9-3/8" | 9" | 9-1/2" |
| Top end | Closed - String Handle | / bar handle | String Handle |
| Bottom end | 1-1/2" MPT | / 1-1/2" male thread/MPT | 1-1/2" MPT |
| Filter area | 42 sq ft | 37.5 sq ft | 40 sq ft |
| Pleats | not listed | 221 | not listed |
| Media weight | 3 oz/yd² | 3 oz/yd² | not listed |
Where to buy
Search any retailer for 5CH-37 or PFF42TC-P4 or FC-2402. 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.
- Aquaterra Spas (OEM 303279) Unicel p.28
- Hot Springs Spas (OEM 303279) Unicel p.39
FAQ
What is the Unicel equivalent of Pleatco PFF42TC-P4?
The catalogs cross-reference Pleatco PFF42TC-P4 to Unicel 5CH-37.
What is the Filbur equivalent of Pleatco PFF42TC-P4?
The catalogs list Filbur FC-2402.
What size is the PFF42TC-P4 filter?
Pleatco lists PFF42TC-P4 as 5-1/4" outside diameter by 9-3/8" long, top: Closed - String Handle, bottom: 1-1/2" MPT, 42 sq ft.
Which OEM part numbers does it replace?
Listed OEM numbers: 303279.
Sources: 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.