Which filter does my Bullfrog hot tub take? Lookup by series and year
It depends on the series and the year. Per Bullfrog’s own parts store: A Series 2018–2022, R Series and X Series from 2018 take the coreless 10-00282 (2-pack 10-00416); STIL from 2018 takes the smaller coreless 10-00281 (2-pack 10-00810); A Series from 2023, M Series and Swim Series use Simplicity flat filters 10-00814. Older spas take threaded cartridges: 10-2870 for A/R/X 2013–2016, 10-2785 for 2003–2012, 10-1085 for 2000–2002 and 10-1086 for 1997–1999. A 2013–2017 A/R/X or 2015–2017 STIL can switch to coreless filters by fitting the 10-00417 cage and cap assembly.
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The cartridges, with equivalents
| Factory part | What it is | Aftermarket equivalents (catalogs) | Rated area | Our page |
|---|---|---|---|---|
| 10-00282 (2-pack 10-00416) | Coreless cartridge for A, R and X Series; slides over the reusable cage Leisure Time lists it as 7-3/4" × 5-3/4" with 3-1/4" openings and 260 pleats; Southern Leisure Spas and Hot Tub Outpost give about 8" × 6-1/4", matching Pleatco. | Pleatco PBF40 (8" × 6-1/4", open 3-3/8" top, 4-1/2" bottom) | 50 sq ft (Bullfrog dealers) or 30 sq ft (Pleatco) | PBF40 |
| 10-00281 (2-pack 10-00810) | Coreless cartridge for STIL (STIL5, STIL7) Leisure Time gives 6-3/4" × 5-3/4" with 3-1/4" openings. | Pleatco PBF17 (6-5/8" × 6-1/4", open 3-3/8" top, 4-1/2" bottom) | About 27 sq ft (Leisure Time) or 18 sq ft (Pleatco) | PBF17 |
| 10-2870 | Threaded Microban cartridge, A/R/X 2013–2016 (also the dealer substitute for 10-2785 and 10-1035) | Unicel 8CH-951 (8" × 5-3/4", 2" SAE); Pleatco PBF36 (8" × 5-7/8", “long thread”) | 35 sq ft (Pleatco; Unicel’s note on the original); Unicel’s 8CH-951 is printed as 50 in its Bullfrog listing and 40 in its spec table | 8CH-951 |
| 10-2785 | Threaded Microban cartridge, all spas and Tadpole 2003–2012. No longer available Unicel says its 8CH-951 “also replaces Bullfrog 6" OAL filter element w/ shorter threaded end”. | Pleatco PBF35 (8" × 5-7/8", “short thread”); Unicel and Filbur do not list this number | 35 sq ft (Pleatco) | not listed |
| 10-1035 | “Filter, Cartridge, 35SF” (Charlottesville dealer). No longer available; substitute 10-2870. No source we found gives its model years | Unicel 8CH-950 (8" × 6", 2" SAE; discontinued by Unicel, which says use 8CH-951); Filbur FC-0536 (8" × 5-3/4"); Pleatco PBF35 | 35 sq ft (dealer, Filbur, Unicel’s note on the original) vs 50 sq ft (Unicel 8CH-950) | 8CH-950 |
| 10-1085 | Cartridge for spas built 2000–2002 | None listed | 50 sq ft (Bullfrog store) | not listed |
| 10-1086 | Cartridge for spas built 1997–1999 (shown out of stock on the Bullfrog store) | None listed | 50 sq ft (Bullfrog store) | not listed |
| 10-3430 | Original STIL cartridge before coreless. No longer available; substitute 10-00281 with cage assembly 10-00417 | None listed | Not given in our sources | not listed |
| 10-00814 | Simplicity flat filters, 4-pack (A Series 2023+, M Series, Swim Series); housing 10-04669 is standard in A, M and Swim Series from 2024 Bullfrog’s store says to clean or replace these monthly. | None listed | Not given in our sources | not listed |
| 10-05338 | Filter for CALM Series spas (2026 on) | None listed | Not given in our sources | not listed |
| 10-00417 | Filter core cage and cap assembly, not a filter. Converts 2013–2017 A/R/X and STIL spas to coreless; replacement part on 2018+ spas | not listed | not listed | not listed |
Equivalents and sizes are from the Unicel 2026 Replacement Guide, the Pleatco 2023 catalog and the Filbur catalog, matched on the Bullfrog number. Where a dealer gives a different size or rating, the table says so. “None listed” means none of the three catalogs lists that Bullfrog number.
Find your series and year
Bullfrog sorts its filters by series and build year rather than by individual model, so the table works the same way: an A7L, A8 or any other A Series spa uses the A Series row for its year. Years come from the product pages on Bullfrog’s own parts store, cross-checked against Leisure Time Inc.’s fitment guide and the list kept by Bullfrog Spa Parts Charlottesville, a Bullfrog dealer.
| Series | Model years | Filter | Where the years come from |
|---|---|---|---|
| All Bullfrog spas | 1997–1999 | 10-1086 (50 sq ft) | Bullfrog store; Charlottesville dealer |
| All Bullfrog spas | 2000–2002 | 10-1085 (50 sq ft) | Bullfrog store; Charlottesville dealer |
| All Bullfrog and Tadpole spas | 2003–2012 | 10-2785 (Microban, threaded). No longer available; the dealer substitute is 10-2870 | Bullfrog store (years); Charlottesville (substitute); Pleatco calls it the “short thread” 2003–2012 cartridge |
| A, R and X Series | 2013–2016 (Bullfrog store) or 2013–2017 (Pleatco) | 10-2870 (Microban, threaded), or coreless 10-00282 after fitting cage assembly 10-00417 | Bullfrog store; Pleatco PBF36 “long thread” |
| STIL (first years) | 2015–2017 | 10-3430 originally (no longer available); now 10-00281 + cage assembly 10-00417 | Bullfrog store (10-00810 page); Charlottesville (10-3430 substitute) |
| A Series | 2018–2022 | 10-00282 coreless (sold as 2-pack 10-00416) | Bullfrog store; Leisure Time |
| R Series | 2018 and later (Bullfrog store) or 2018–2022 (Leisure Time) | 10-00282 coreless (2-pack 10-00416) | Bullfrog store; Leisure Time |
| X Series | 2018 on (“all X Series” per the Bullfrog store; Leisure Time lists 2018–2026) | 10-00282 coreless (2-pack 10-00416) | Bullfrog store; Leisure Time |
| STIL (STIL5, STIL7) | 2018 and later | 10-00281 coreless (2-pack 10-00810) | Bullfrog store; Leisure Time |
| A Series | 2023 and later | Simplicity flat filters 10-00814 (4-pack) | Bullfrog store; Leisure Time; Bullfrog filter-care article |
| M Series | All (Bullfrog store) or 2020 on (Leisure Time) | Simplicity flat filters 10-00814 | Bullfrog store; Leisure Time |
| Swim Series | All (Bullfrog store) or 2020 on (Leisure Time) | Simplicity flat filters 10-00814 | Bullfrog store; Leisure Time |
| CALM Series | 2026 and later | 10-05338 (drop-in filter) | Bullfrog store; Charlottesville dealer |
Threaded or coreless: how to tell in ten seconds
Lift out the cartridge. If a plastic cage stays in the spa and the pleated sleeve slides off it, you have the coreless system (10-00282 or 10-00281). If the whole cartridge unscrews as one piece with a handle on top, it is a threaded cartridge (10-2870 or older). For A (2022 and earlier), R, X and STIL spas, Bullfrog’s filter-care article describes removal as turning the filter-core cap counter-clockwise and sliding the cartridge up off the core. A flat, rectangular filter is a Simplicity filter.
Where the sources disagree
- When coreless started. Bullfrog’s store and Leisure Time say 2018. Pleatco labels both coreless cross-references (PBF40, PBF17) “2017–Current”, and labels the threaded PBF36 “2013–2017”. Bullfrog’s store limits the original 10-2870 to 2013–2016, while its cage-assembly page offers the conversion for 2013–2017 spas. For a 2017 spa, look at what is installed.
- R Series end year. Bullfrog’s 10-00416 page says R Series 2018 and later; Leisure Time and Southern Leisure Spas say R Series 2018–2022.
- Coreless in pre-2013 spas. The Charlottesville dealer lists 10-00282 for “All 2003–2012 except STIL” when used with the 10-00417 cage, and Hot Tub Outpost says 2002 and newer except STIL. Bullfrog’s own cage page only claims 2013 and newer. If your spa is older than 2013, ask a dealer before buying the cage.
- Size and rating of the coreless filters. 10-00282: 7-3/4" × 5-3/4" and 50 sq ft (Leisure Time) vs 8" × 6-1/4" (Pleatco, Southern Leisure, Hot Tub Outpost) and 30 sq ft for Pleatco’s PBF40. 10-00281: about 27 sq ft (Leisure Time) vs 18 sq ft (Pleatco PBF17).
- Rating of the threaded cartridges. The Charlottesville dealer and Filbur call 10-1035 a 35 sq ft cartridge, and Unicel notes the original is 35 sq ft, but Unicel rates its own 8CH-950 at 50. Unicel’s 8CH-951 (for 10-2870) appears as 50 sq ft in the Bullfrog listing and 40 in the spec table.
- Is 10-2870 for 2003 on? The Charlottesville dealer describes 10-2870 as “2003–Present except STIL” because it replaces 10-2785; Bullfrog’s store describes it as the original cartridge for 2013–2016 A/R/X spas.
Known limits
- No source we found gives dimensions for 10-1085, 10-1086, 10-3430, the Simplicity filters or the CALM filter, and none of the three aftermarket catalogs lists them.
- No catalog lists an aftermarket version of the Simplicity or CALM filters.
- The 10-1035 is listed by Unicel and Filbur, but no source we found says which years it was fitted.
How to confirm yours
- Read the number on the old cartridge’s end cap or label and search it here.
- No number? Measure diameter and length (our filter-size guide shows how). A threaded 8" × about 6" cartridge is the 10-2870/10-2785 family; a coreless 8" sleeve is 10-00282; a coreless sleeve under 7" is the STIL 10-00281.
- Bullfrog’s care article says to clean pleated cartridges every 3–6 weeks and replace them every 1–2 years; see also how often to clean a hot tub filter.
Why one cartridge size can carry two different square-foot ratings: our explainer with Unicel’s pleat-count table.
Sources
- Bullfrog Spas official parts store: Filters category and product pages (10-1086, 10-1085, 10-2785, 10-2870, 10-00416, 10-00810, 10-00417, 10-00814, 10-05338, 10-04669; fetched 2026-10-27)
- Bullfrog Spas official store: Coreless Filter for A, R and X Series, 2-pack 10-00416 (series and years)
- Bullfrog Spas official store: Filter Core Cage & Cap Assembly 10-00417
- Bullfrog Spas: How to clean, take care of and replace a hot tub filter (filter types by series, cleaning intervals)
- Leisure Time Inc.: Hot Tub Filter Fitment Guide (Bullfrog section)
- Leisure Time Inc.: Bullfrog A/R/X 10-00282 product page (specifications)
- Leisure Time Inc.: Bullfrog STIL 10-00281 product page (specifications)
- Bullfrog Spa Parts Charlottesville: Replacement filters (years, discontinued parts and substitutes)
- Southern Leisure Spas: Bullfrog coreless filters 10-00416 (dimensions, series years)
- Hot Tub Outpost: Bullfrog 10-00282 coreless filter (dimensions)
- Pleatco 2023 Catalog: PBF17, PBF35, PBF36, PBF40 (sizes, ratings, application years)
- Unicel 2026 Replacement Guide: Bullfrog Spas cross-reference and spec table (8CH-950, 8CH-951)
- Filbur Catalog & Reference Guide: Bullfrog (FC-0536)
This page summarizes published catalogs and dealer fitment tables; always follow your own spa’s owner’s manual. See our disclaimer and methodology.