Pleatco PTL20W-SV-P4 = Unicel 6CH-25 = Filbur FC-0305
20 sq ft hot tub filter, 6" diameter × 5-1/2" long. Top: Handle · Bottom: 1-1/2" MPT. Pleatco application: Softub; Leisure Bay; 6 x 5 1/2, TSC.
Interchangeable cartridges
- Unicel 6CH-25 confirmed by: Pleatco p.47 (Unicel to Pleatco cross reference) Unicel p.12 (Cartridges by series (dimensional listing))
- Filbur FC-0305 confirmed by: Pleatco p.48 (Filbur to Pleatco cross reference) Filbur p.34 (Reverse cross reference (Unicel to Filbur)) Filbur p.10 (Dimensional cartridge listing)
Check before you order
- Unicel 6CH-25 rates it 25 sq ft (vs 20 sq ft); filter area ratings differ by maker.
- Filbur FC-0305 rates it 25 sq ft (vs 20 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 PTL20W-SV-P4 source | Unicel 6CH-25 source | Filbur FC-0305 source |
|---|---|---|---|
| Outside diameter | 6" | 6" | 6" |
| Length | 5-1/2" | 5-1/2" | 5-1/2" |
| Top end | Handle | / semi-circular handle | Handle |
| Bottom end | 1-1/2" MPT | / 1-1/2" male thread/MPT | 1-1/2" MPT |
| Filter area | 20 sq ft | 25 sq ft | 25 sq ft |
| Pleats | not listed | 205 | not listed |
| Media weight | 3 oz/yd² | 3 oz/yd² | not listed |
Where to buy
Search any retailer for 6CH-25 or PTL20W-SV-P4 or FC-0305. 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 |
|---|---|
90-802 | Pleatco p.33: OEM part # column Unicel p.55: OEM cross reference: Softub |
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.
- Softub (OEM 90-802) Unicel p.55
- Sunrise Spas Unicel p.59
FAQ
What is the Unicel equivalent of Pleatco PTL20W-SV-P4?
The catalogs cross-reference Pleatco PTL20W-SV-P4 to Unicel 6CH-25.
What is the Filbur equivalent of Pleatco PTL20W-SV-P4?
The catalogs list Filbur FC-0305.
What size is the PTL20W-SV-P4 filter?
Pleatco lists PTL20W-SV-P4 as 6" outside diameter by 5-1/2" long, top: Handle, bottom: 1-1/2" MPT, 20 sq ft.
Which OEM part numbers does it replace?
Listed OEM numbers: 90-802.
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.