Which filter does my Softub take? Lookup by year and model
Softubs use a snap-on spa filter that pushes over the suction cover (drain cap), not a threaded cartridge. If your Softub was built in July 2009 or later (T-140, T-220, T-300) it takes the 5020, Softub P/N 2003905, which fits the 5-1/2" drain cap held by two screws. SoftubDirect says that covers about 90% of owners. Older Softubs with a 4" cap held by one screw take the 5015 (P/N 2005400) or the shorter 5010 (P/N 2002200). Count the screws on the cap if you are not sure of the year. Unicel, Pleatco and Filbur do not list the snap-on filters.
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The cartridges, with equivalents
| Factory part | What it is | Equivalents (dealers and catalogs) | Rated area | Our page |
|---|---|---|---|---|
| 5020 (P/N 2003905) | Snap-on, closed top, fits the 5-1/2" two-screw drain cap; Softubs built July 2009 and newer (T-140, T-220, T-300). Current version has blue end caps (SpaStore) | Great Barrier 8553 (aftermarket, per dealers). Not in the Unicel, Pleatco or Filbur catalogs | 6" × 7-3/4" (SpaStore); area not given | not listed |
| 5015 (P/N 2005400) | Snap-on, 4" opening, for the 4" one-screw drain cap; Softubs built before July 2009 | Great Barrier 8555 / 8555CA (ezhottubparts: 35 sq ft, closed top, 4" slip collar). Unicel and Filbur: none | 6" × 7-3/4" (SpaStore) | not listed |
| 5010 (P/N 2002200) | Shorter snap-on with an offset hole of about 3-3/4"; older T-140 and the Chameleon | None found | 6" × 5-1/2", 25 sq ft (SoftubDirect) | not listed |
| 4CH-23DF (Diamond Filtration) | Screw-on filter for an older Softub whose 4" drain cap broke and left a threaded pipe exposed (SoftubDirect) | Sold under its own number | 5" diameter, 1-1/2" MPT | not listed |
| 90-802 (catalogs only) | Threaded handle-top cartridge that Unicel and Pleatco list for Softub (Pleatco also names Leisure Bay); no Softub dealer we found sells it for a Softub | Unicel 6CH-25; Pleatco PTL20W-SV-P4; Filbur FC-0305 (filed under Softsider) | 6" × 5-1/2"; 25 sq ft (Unicel, Filbur), 20 sq ft (Pleatco) | 6CH-25 |
| No OEM number (Unicel only) | Small threaded cone-top cartridge, 1-1/2" MPT, listed for Softub by Unicel only | Unicel 4CH-20 | 4-5/8" × 6-3/4", 20 sq ft | 4CH-20 |
Softub’s owner’s manual does not print filter part numbers. The 5020, 5015 and 5010 numbers, Softub P/Ns and year split come from Softub dealers. The threaded cartridges at the bottom are the ones the Unicel, Pleatco and Filbur catalogs list for Softub.
Find your year
Softub does not sort filters by model: the dividing line is mid-2009, when the suction cover (drain cap) changed. The table is built from SoftubDirect, SpaStore.com, Simply Softub Spas and ezhottubparts listings.
| Softub | Built | Filter | Aftermarket |
|---|---|---|---|
| Softub T-140, T-220, T-300 (and Portico, per one dealer) | July 2009 and newer (June 2009 in some dealer listings) | 5020 snap-on, P/N 2003905; 5-1/2" drain cap held by 2 screws | Great Barrier 8553 (aftermarket) |
| Older Softubs | Before July 2009 | 5015 snap-on, P/N 2005400; 4" drain cap held by 1 screw | Great Barrier 8555 / 8555CA (aftermarket) |
| Older T-140 and the Chameleon | Before July 2009 | 5010 short snap-on, P/N 2002200 | not listed |
| Older Softub with a broken 4" drain cap and an exposed threaded pipe | Before July 2009 | Screw-on “thinner” filter | Diamond Filtration 4CH-23DF (1-1/2" MPT, 5" diameter) |
How the filter comes off, and how often
Softub’s 2025 owner’s manual says the hot tub filter snaps over the gray or pearl suction covers and should be removed only when the spa is warm, so the collar is soft enough to slide off; soaking the collar in warm water helps. The manual says to clean the filter at least monthly and replace it at least once a year. The manual describes one filter, with a filter sock, that snaps onto either of the two suction covers.
Where the sources disagree
- June or July 2009. SoftubDirect’s guide says July 2009 and its 5020 listing says June 2009 and later; Simply Softub Spas says “purchased after June 2009”; SpaStore says July 2009. SoftubDirect also mixes “made” and “bought” in 2009. For a 2009 tub, count the drain-cap screws instead.
- Drain-cap size. SoftubDirect and Simply Softub Spas say the newer cap is 5-1/2"; ezhottubparts calls it 5".
- Filter area. ezhottubparts rates the 8555 at 35 sq ft; SoftubDirect rates the shorter 5010 at 25 sq ft. None of the sources gives an area for the 5020 or 5015.
- Filbur FC-9900. ezhottubparts lists Filbur FC-9900 for the 2009-and-newer filter. We could not find FC-9900 in the Filbur catalog.
- Threaded catalog cartridges. Unicel lists 6CH-25 (OEM 90-802) and 4CH-20 for Softub, and Pleatco lists PTL20W-SV-P4 for Softub and Leisure Bay. Softub’s manual and the Softub dealers describe only snap-on filters (plus the 4CH-23DF for a broken cap). We could not find which Softubs, if any, took the threaded cartridges.
- 90-802 rating. Unicel and Filbur rate it 25 sq ft; Pleatco rates PTL20W-SV-P4 at 20.
Known limits
- Softub does not publish part numbers in its manual; the snap-on numbers come from dealers.
- The 4CH-20 listing stays flagged: only Unicel lists it for Softub, and the retailer tables that repeat it give no OEM number or model.
- The snap-on filters are not in our dataset because the Unicel, Pleatco and Filbur catalogs do not list them.
How to confirm yours
- With the spa warm, pull the filter and look at the drain cap: two screws and a 5-1/2" cap means the 5020; one screw and a 4" cap means the 5015 or 5010 (measure the length: 7-3/4" or 5-1/2").
- A threaded cartridge instead? Read its number and search it here, or measure it with our filter-size guide, and compare with the Softub brand table.
- See how often to replace a hot tub filter.
Why one cartridge size can carry two different square-foot ratings: our explainer with Unicel’s pleat-count table.
Sources
- Softub: Owner’s manual (domestic), October 2025 (snap-on filter, removal, cleaning and replacement)
- SoftubDirect: Which Softub filter do I need? (5020 vs older filters, drain-cap test)
- SoftubDirect: Softub filter 5020 (P/N 2003905; T-140, T-220, T-300)
- SoftubDirect: Snap-on filter 5010 for much older Softubs (P/N 2002200, 25 sq ft)
- SoftubDirect: Diamond thinner screw-on filter for older Softubs (4CH-23DF)
- SpaStore.com: Softub filter cartridges (5020 / 2003905 and 5015 / 2005400, sizes)
- Simply Softub Spas: 5020 filter for tubs purchased after 2009
- ezhottubparts: Softub filters (5020 / 2003905, Great Barrier 8553, 8555)
- ezhottubparts: Softub 8555 pre-2009 snap-on filter (35 sq ft, 4" slip collar)
- Unicel 2026 Replacement Guide: Softub cross-reference (printed p. 51) and spec tables
- Pleatco 2023 Catalog: PTL20W-SV-P4 (Softub; Leisure Bay; OEM 90-802)
- Filbur Catalog & Reference Guide: Softsider Spas, FC-0305 (OEM 90-802)
This page summarizes published catalogs and dealer fitment tables; always follow your own spa’s owner’s manual. See our disclaimer and methodology.