Which filter does my Sundance hot tub take? Lookup by model, year and serial number

Reviewed October 26, 2026

Sundance changed filter systems several times, so the year matters. In Sundance Spas Norway’s model table: 880 and 980 Series spas from about 2005/2006 to 2023 take the two-piece MicroClean Ultra set (6473-165 outer + 6473-164 inner), with the one-piece 6540-488 as an alternative; 780 Series spas take the two-part MicroClean (6540-501 pleated + 6540-502 disposable upper), also with 6540-488 as the alternative; 680 Series spas through 2022 take the 373045 and 2023+ models take the MicroClean Mini (6473-249S + 6473-283S); and 2024+ 880 models take MicroClean Ultra II (6473-452S + 6473-453S). Pre-2002 spas mostly use the 6540-490 or 6540-483.

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The cartridges, with equivalents

Sizes and equivalents are from the Unicel 2026 Replacement Guide, the Pleatco 2023 catalog and the Filbur catalog, matched on the factory number; “none listed” means none of the three lists that number. Sundance numbers often carry a trailing S (6473-165S); it is the same part.

Find your model (with serial ranges)

This table reproduces Sundance Spas Norway’s filter overview for all models from 1995 (version dated May 2026). Sundance Norway lists a serial-number range for most rows and asks owners to check against the serial number. “Alternative” is the part it lists as an alternative fit. Model names and years are as Sundance Norway prints them, including its spelling “Berkely”.

Berkely, Brook and Paisley (2020 on, serials starting E2…) are listed with SC817. We could not find that number in any of the three aftermarket catalogs, so confirm it with a Sundance dealer.

Which system is in my spa, and how often does it need attention?

A Sundance dealer, The Sundance Spa Store, publishes these care intervals by system:

Filbur prints “Replace after 3 months of use” on its FC-2812 version of the 6540-502 disposable upper. For our general advice, see how often to replace a hot tub filter.

Where the sources differ

• 880 Series, 2005–2008. Leisure Time Inc. lists the 6540-507 MicroClean Plus for 880 Maxxus, Cameo and Optima 2005–2008 and Altamar, Majesta, Marin and Capri 2006–2008. Sundance Norway puts those models on the MicroClean Ultra 6473-165/164 from 2005 or 2006. Check the old cartridge: the MicroClean Plus is a single cartridge, the Ultra is an outer plus an inner core.
• 980 Series start and end dates. Leisure Time lists Claremont and Kingston for 2017–2025. A Sundance dealer (Snow Valley Spas) lists Claremont and Kingston from October 2016, and Lisbon and Odessa for 2019–March 2021. Sundance Norway gives 2017+ and 2019+.
• Bahia, Cayman, Palermo and Lagunas 2003–2005, Capri 2001 and Caprio 2000–2001. Sundance Norway lists the one-piece 6540-488 as the main filter for these and the 501/502 pair as the alternative, the reverse of later 780 models.
• 680 Series, early 2023. Leisure Time says some early-2023 680 spas may still use the 373045. The serial ranges above are the best way to tell.
• 2024 and 2026 changes. Leisure Time says to confirm the system on 2024 880 spas, and lists a MicroClean Ultra II Lite for 2026 780 models (Bristol, Chelsee, Dover, Hamilton, Montclair) using a 6473-608S outer with the 6473-453S inner. Sundance Norway’s table does not list the Ultra II Lite yet.
• Pre-2006 vs 2006+ one-piece cartridges. Unicel splits the 6540-488 into C-8326 (with core plug, for pre-2006 spas) and C-8327 (no plug, after 2005). Leisure Time’s tables follow the same split.

Sundance Norway is a European distributor, and Leisure Time and Snow Valley are North American dealers. Model names match across them, but production dates can differ by market.

How to confirm yours

1. Read the part number on the old cartridge or cartridges. A two-piece set (outer plus inner core) is MicroClean Ultra or Mini; a pleated cartridge plus a short disposable top is MicroClean.
2. Compare your spa’s serial number with the ranges in the table above, as Sundance Norway advises.
3. If the label is unreadable, measure diameter and length (see our filter-size guide) and compare with the sizes above.

Why one cartridge size can carry two different square-foot ratings: our explainer with Unicel’s pleat-count table.

Sources

1. Sundance Spas Norway: Filteroversikt alle modeller fra 1995 (filter overview by model, year and serial number, May 2026)
2. Leisure Time Inc.: Hot Tub Filter Fitment Guide (Sundance tables; fetched 2026-10-26)
3. Snow Valley Spas: 6473-165S MicroClean Ultra outer (size and model years)
4. The Sundance Spa Store: Filter cleaning and maintenance instructions (intervals by series)
5. Unicel 2026 Replacement Guide: Sundance cross-reference and spec tables
6. Filbur Catalog & Reference Guide: Sundance section (FC-2760, FC-2769/2771/2772, FC-2770, FC-2780, FC-2791, FC-2810, FC-2812)
7. Pleatco 2023 Catalog: Sundance cross-reference (PSD125-2000, PSD85-2002, PPS750, PSD125U, PSD75)

This page summarizes published catalogs and dealer fitment tables; always follow your own spa’s owner’s manual. See our disclaimer and methodology.