Pleatco PLBS100 = Unicel C-5397 = Filbur FC-2972
100 sq ft hot tub filter, 5-5/16" diameter × 17-3/4" long. Top: 2-1/8" open · Bottom: 2-1/8" open. Pleatco application: Rainbow, Waterway, Leisure Bay, S2/G2 Spa 100.
Interchangeable cartridges
- Unicel C-5397 confirmed by: Pleatco p.47 (Unicel to Pleatco cross reference) Unicel p.11 (Cartridges by series (dimensional listing))
- Filbur FC-2972 confirmed by: Pleatco p.48 (Filbur to Pleatco cross reference) Filbur p.33 (Reverse cross reference (Unicel to Filbur)) Filbur p.10 (Dimensional cartridge listing)
Check before you order
- Unicel C-5397 rates it 80 sq ft (vs 100 sq ft); filter area ratings differ by maker.
- Filbur FC-2972 rates it 80 sq ft (vs 100 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 PLBS100 source | Unicel C-5397 source | Filbur FC-2972 source |
|---|---|---|---|
| Outside diameter | 5-5/16" | 5-5/16" | 5-5/16" |
| Length | 17-3/4" | 17-13/16" | 17-3/4" |
| 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 | 100 sq ft | 80 sq ft | 80 sq ft |
| Pleats | not listed | 223 | not listed |
| Media weight | 3 oz/yd² | 3 oz/yd² | not listed |
Where to buy
Search any retailer for C-5397 or PLBS100 or FC-2972. 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.
- Leisure Bay Spas (models: S2/G2 Spa) Unicel p.43
- Pentair Pool Prod - Rainbow Plastics (OEM R173601) Unicel p.53
- QCA Unicel p.53
- Rec Warehouse (OEM 303434) Unicel p.54
- Waterway Plastics (models: 100 sq.ft. top load; OEM 817-0016) Unicel p.64
FAQ
What is the Unicel equivalent of Pleatco PLBS100?
The catalogs cross-reference Pleatco PLBS100 to Unicel C-5397.
What is the Filbur equivalent of Pleatco PLBS100?
The catalogs list Filbur FC-2972.
What size is the PLBS100 filter?
Pleatco lists PLBS100 as 5-5/16" outside diameter by 17-3/4" long, top: 2-1/8" open, bottom: 2-1/8" open, 100 sq ft.
Which OEM part numbers does it replace?
Listed OEM numbers: 817-0016, 303434, R173601.
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.