Listing we opened and checked. Match the diameter, length and both fittings on this page before you order. The price is on Amazon; we do not print one.
Bullfrog spa filter (C-4950)
Bullfrog Spas
Replacement numbers
Unicel C-4950, Pleatco PRB50-IN
Fits Bullfrog Spas.
Diameter 4-15/16" (125 mm)Length 13-5/16" (338 mm)50 sq ftUnicel C-4950
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| Unicel | C-4950 |
|---|---|
| Pleatco | PRB50-IN |
| Filbur | FC-2390 |
| Top | 2-1/8" (54 mm) / open |
| Bottom | 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. 50 sq ft media.
Bullfrog Spas is the group name on the Bullfrog row C-4950 cartridge. Match these numbers: Unicel C-4950; Pleatco PRB50-IN; Filbur FC-2390. 4-15/16" across, 13-5/16" long, top 2-1/8" / open, bottom 2-1/8" / open, 50 sq ft.
C-4950 is easy to confuse on the Bullfrog table. PBF17 differs by no Unicel number, Pleatco PBF17, no Filbur number, 6-5/8" diameter, 6-1/4" long, top 3-3/8" open (coreless), bottom 4-1/2" open (coreless), 18 sq ft, OEM 10-00281, note says Pleatco: Bullfrog 18 coreless, 2017-current. Leisure Time Inc. rates the OEM 10-00281 cartridge at approximately 27 sq ft and notes 2015-2017 STIL spas need Filter Core Cage & Cap Assembly 10-00417; Leisure Time Inc.: Coreless cartridge; the correct filter cage and cap must be installed.. PBF40 differs by no Unicel number, Pleatco PBF40, no Filbur number, 8" diameter, 6-1/4" long, top 3-3/8" open (coreless), bottom 4-1/2" open (coreless), 30 sq ft, OEM 10-00282, note says Pleatco: Bullfrog 30 coreless, 2017-current. Leisure Time Inc. rates the OEM 10-00282 cartridge at 50 sq ft and notes 2013-2017 A/R/X spas need the Filter Core Cage & Cap Assembly; 2023-and-newer A Series use Simplicity flat filters; Leisure Time Inc.: Coreless cartridge; the correct filter cage and cap must be installed. 2023-and-newer A Series models use Simplicity flat filters..
Left blank on purpose: no model/model-year fitment in sources; Unicel lists no OEM part number for this brand entry.
Where those figures are printed: Unicel 2026 Replacement Guide on C-4950 (OEM cross reference (Bullfrog section), PDF p.30 (printed p.26); spec table PDF p.9 (printed p.5)). Pleatco 2023 Catalog on C-4950 (Unicel-to-Pleatco cross reference, PDF p.47). Filbur Catalog & Reference Guide on C-4950 (Product by Pool/Spa Manufacturer (OEM), Bullfrog, printed p.29 (PDF p.15)).
If you know the Bullfrog model and not the part number, use the Bullfrog 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. Brand notes: Bullfrog filters. Number formats: how Filbur, Unicel and Pleatco numbers compare.
The same C-4950 number is also on the Caldera, Jacuzzi, Sundance, Beachcomber, Coleman Spas pages.
Other Bullfrog cartridges
- PBF17 cartridge (OEM 10-00281), 6-5/8" (168 mm) × 6-1/4" (159 mm)
- PBF40 cartridge (OEM 10-00282), 8" (203 mm) × 6-1/4" (159 mm)
- 8CH-950 cartridge (OEM 10-1035), 8" (203 mm) × 6" (152 mm)
- 8CH-951 cartridge (OEM 10-2870), 8" (203 mm) × 5-3/4" (146 mm)
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
-
Leisure Time O Filter Clean Cartridge Cleaner Listing title: cartridge cleaner, 32 fl oz.
-
SpaGuard Filter Cleaner Listing title: filter cleaner for spas and hot tubs, 1 quart.
-
AquaChek SPA 6-in-1 Test Strips Listing title: reads total bromine, total chlorine, free chlorine, pH, total alkalinity and total hardness.
Unicel C-4950 Listing we opened and checked. Match the diameter, length and both fittings on this page before you order. The price is on Amazon; we do not print one.
Sources
- Unicel 2026 Replacement Guide: OEM cross reference (Bullfrog section), PDF p.30 (printed p.26); spec table PDF p.9 (printed p.5) (PDF)
- Pleatco 2023 Catalog: Unicel-to-Pleatco cross reference, PDF p.47 (PDF)
- Filbur Catalog & Reference Guide: Product by Pool/Spa Manufacturer (OEM), Bullfrog, printed p.29 (PDF p.15) (PDF)
Not in sources: no model/model-year fitment in sources; Unicel lists no OEM part number for this brand entry.