Arctic Spas spa filter (C-4326)

Arctic Spas (Unicel lists Arctic under Blue Falls Mfg. Ltd., Canada)

Replacement numbers

Unicel C-4326, Pleatco PRB25-IN

Fits Arctic Spas (Unicel lists Arctic under Blue Falls Mfg. Ltd., Canada).

Diameter 4-15/16" (125 mm)Length 13-5/16" (338 mm)25 sq ft

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UnicelC-4326
PleatcoPRB25-IN
FilburFC-2375
Top2-1/8" (54 mm) / open
Bottom2-1/8" (54 mm) / open
Ø 4-15/16" (125 mm)13-5/16" (338 mm)Side view · end views belowTopBottom
Top: 2-1/8" (54 mm) / open
Bottom: 2-1/8" (54 mm) / open
Drawn to scale from the listed diameter and length and open-end sizes. Handles, threads and closed ends are drawn as symbols, not to scale. 25 sq ft media.

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Arctic Spas (Unicel lists Arctic under Blue Falls Mfg. Ltd., Canada) is the group name on the Arctic Spas row C-4326 cartridge. Match these numbers: Unicel C-4326; Pleatco PRB25-IN; Filbur FC-2375. 4-15/16" across, 13-5/16" long, top 2-1/8" / open, bottom 2-1/8" / open, 25 sq ft.

Catalog note for PRB25-IN: Unicel has no Arctic table of its own and says "see Blue Falls Mfg. Ltd. (Canada)"; Filbur lists this part under both Arctic Spas and Blue Falls Mfg. Neither source gives an OEM number.

Left blank on purpose: no OEM part number in sources; no model/model-year fitment in sources.

Where those figures are printed: Unicel 2026 Replacement Guide on C-4326 (OEM cross reference: Arctic Spas entry (PDF p.28, printed p.24) points to Blue Falls Mfg. Ltd. (Canada), PDF p.29 (printed p.25); spec table PDF p.9 (printed p.5)). Pleatco 2023 Catalog on C-4326 (Unicel-to-Pleatco cross reference, PDF p.47 (C-4326 = PRB25-IN)). Filbur Catalog & Reference Guide on C-4326 (Product by Pool/Spa Manufacturer (OEM), Arctic Spas, printed p.27 (PDF p.14)).

If you know the Arctic Spas model and not the part number, use the Arctic Spas filter by model and year lookup.

Check the cartridge you removed

Measure diameter, length, and both ends, then compare them with the figures above. The steps are in the measuring guide. Why the bottom decides whether it seals: open-end vs threaded filters. Power, the retainer, and not running the spa empty: how to install a cartridge. Number formats: how Filbur, Unicel and Pleatco numbers compare.

The same C-4326 number is also on the Hot Spring, Hot Spot, Jacuzzi, Beachcomber, PDC Spas pages.

Every number on this row, on one screen: cross-reference lookup. Published clean and replace intervals for this cartridge, and a buy link for the numbers above: replacement schedule and reorder. The interval comparison by brand: calculator.

Cleaner and test strips

Hose rinse and soak steps are in how to clean a cartridge. Named cleaners and strips are in filter cleaners and test strips.

Filter cleaner and test strips

Sources

Not in sources: no OEM part number in sources; no model/model-year fitment in sources.