Pleatco PLBS50 = Unicel C-5345 = Filbur FC-2970

50 sq ft hot tub filter, 5-5/16" diameter × 10-1/8" long. Top: 2-1/8" open · Bottom: 2-1/8" open. Pleatco application: Leisure Bay, Dynasty Spas, Waterway, Rainbow.

Interchangeable cartridges

Unicel C-5345 confirmed by: Pleatco p.47 (Unicel to Pleatco cross reference) Unicel p.11 (Cartridges by series (dimensional listing))
Filbur FC-2970 confirmed by: Pleatco p.48 (Filbur to Pleatco cross reference) Filbur p.33 (Reverse cross reference (Unicel to Filbur))

Check before you order

Unicel C-5345 rates it 45 sq ft (vs 50 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 PLBS50 source	Unicel C-5345 source
Outside diameter	5-5/16"	5-5/16"
Length	10-1/8"	10-1/8"
Top end	2-1/8" open	2-1/8" / open
Bottom end	2-1/8" open	2-1/8" / open
Filter area	50 sq ft	45 sq ft
Pleats	not listed	230
Media weight	3 oz/yd²	3 oz/yd²

Where to buy

Search any retailer for C-5345 or PLBS50 or FC-2970. These are the same cartridge under different brand names.

In The Swim (link coming soon)FiltersFast (link coming soon)Amazon (link coming soon)

Some links may be affiliate links. See our disclosure.

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
`817-0014`	Pleatco p.32: OEM part # column Unicel p.64: OEM cross reference: Waterway Plastics
`173584`	Pleatco p.32: OEM part # column Unicel p.54: OEM cross reference: Rec Warehouse
`R173584`	Pleatco p.32: 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.

Dynasty Spas Unicel p.34
Garden Leisure Unicel p.36
Leisure Bay Spas (models: S2/G2 Spa) Unicel p.43
Rec Warehouse (OEM 173584) Unicel p.54
Rocky Mountain Spas Unicel p.54
Waterway Plastics (models: 45 sq.ft. top load; OEM 817-0014) Unicel p.64

FAQ

What is the Unicel equivalent of Pleatco PLBS50?

The catalogs cross-reference Pleatco PLBS50 to Unicel C-5345.

What is the Filbur equivalent of Pleatco PLBS50?

The catalogs list Filbur FC-2970.

What size is the PLBS50 filter?

Pleatco lists PLBS50 as 5-5/16" outside diameter by 10-1/8" long, top: 2-1/8" open, bottom: 2-1/8" open, 50 sq ft.

Which OEM part numbers does it replace?

Listed OEM numbers: 817-0014, 173584, R173584.

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.