PBF40 / FC-9900
30 sq ft replacement filter cartridge • 8″ OD × 6.25″ long
Bullfrog switched to a coreless cartridge design in 2018, and the PBF40 is it, used across the A-series, R-series, and X-series from that year forward. Coreless means there's no rigid plastic center tube. The pleats collapse inward when you pull it, which makes it lighter and, Bullfrog argues, easier to rinse clean. It's a 30-square-foot element, and unlike most cartridges here it has only a Filbur cross-reference, FC-9900, alongside the Bullfrog 10-00282 and Wellspring 1000282 numbers. Unicel doesn't make a listed equivalent. If your Bullfrog predates 2018, you need the older PBF35 instead, so check the year before you buy.
Compare on Amazon
PBF40 replacements on Amazon
The buttons below pull up Amazon results for each cross-reference part number. Same physical cartridge, different stickers, often different prices. Cross-shop and pick the cheapest option that has solid recent reviews.
Cross-Reference & Interchangeable Part Numbers
| Brand | Part Number | Type |
|---|---|---|
| Pleatco | PBF40 | Primary |
| Filbur | FC-9900 | Equivalent |
| OEM | Bullfrog 10-00282 | Original Equipment |
| OEM | Wellspring 1000282 | Original Equipment |
Always verify dimensions and end-cap type before purchasing a replacement.
Compatible Hot Tubs & Spas
The PBF40 (or any of its cross-references) fits these spa models. Cartridge sizing occasionally shifted between model years, so it's worth confirming against your owner's manual or the cartridge label.
| Brand | Model |
|---|---|
| Bullfrog | A-Series 2018+ |
| Bullfrog | R-Series 2018+ |
| Bullfrog | X-Series |
Frequently Asked Questions
What are the dimensions of the PBF40?
The PBF40 is 8 inches in outer diameter, 6.25 inches long, with an open top and an open bottom. Total filtration area is 30 square feet. Before ordering, pull your existing cartridge and measure it yourself, or check the label inside the housing. OD and length both have to match within about an eighth of an inch, and the end-cap style needs to match exactly so the cartridge seats properly when the lid closes.
What other part numbers are interchangeable with the PBF40?
PBF40 is the same physical cartridge as FC-9900, plus OEM versions like Bullfrog 10-00282, Wellspring 1000282. Same dimensions (8" × 6.25"), same open top, same open bottom. The Pleatco, Unicel, and Filbur boxes ship the same media inside, just with different stickers. The only thing to watch is the end-cap style: if a cross-reference has a slightly different cap design, it may not seat right in your housing.
Is the Bullfrog 10-00282 the same filter as the PBF40?
Yes. Bullfrog 10-00282 is an OEM number, the code the tub or pool builder stamps on the cartridge they ship. The filter itself is made by Pleatco, Unicel, or Filbur, so Bullfrog 10-00282 (along with Wellspring 1000282) and PBF40, FC-9900 all point to one interchangeable cartridge. Buy whichever is cheapest with solid recent reviews, and just check that the dimensions match your old cartridge before you order.
How often should I replace the PBF40?
Mid-size spa cartridges like the PBF40 (30 sq ft) usually last 12 to 24 months. It shows up most often in Bullfrog tubs. The real driver is use: a tub that gets daily soaks for a couple of people burns through cartridges about twice as fast as one used a few times a month. A good rhythm is a monthly hose rinse, a deep soak in cleaner at every water change (every three to four months), and replacement once the pleats tear, the seams stain brown, or a soak no longer brings post-clean pressure back to baseline.
How do I clean the PBF40?
The PBF40 has open ends on both top and bottom, so water flows straight through. Pull the cartridge from the housing and hose it down. Hit the pleats from above at about a 45-degree angle so water rinses debris out instead of packing it deeper, and work top to bottom while rotating the cartridge. Skip the pressure washer. The high pressure tears or collapses pleats, and once that happens you've lost media that doesn't come back. Every few months (or at every water change, whichever comes first), do a deep clean: overnight soak in a hot tub filter cleaner, then a thorough rinse. If your cartridge has a closed end cap, let it dry before reinstalling so you don't trap moisture inside the cartridge core.
Which hot tubs and spas use the PBF40?
The PBF40 is compatible with: Bullfrog A-Series 2018+, Bullfrog R-Series 2018+, Bullfrog X-Series. Confirm against your owner's manual or the label inside the filter compartment, since some brands changed cartridge sizing between model years.
Dimensions
Specifications
| Outer Diameter | 8″ |
|---|---|
| Length | 6.25″ |
| Top Type | Open (no end cap) |
| Bottom Type | Open (no end cap) |
| Filtration Area | 30 sq ft |
| Primary Brand | Pleatco |
| Part Number | PBF40 |
Fitment notes
Coreless design. Bullfrog A, R, and X Series 2018+.