Marquis Spas OEM 20690 spa filter (5CH-512)

Marquis Spas (listed as Pacific Marquis in the Filbur catalog)

Replacement numbers

Unicel 5CH-512

Fits Marquis Spas OEM 20690, 370-0699.

Diameter 5-3/16" (132 mm)Length 16" (406 mm)50 sq ft3 models listed

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Unicel5CH-512
Pleatconot found in source
Filburnot found in Filbur catalog
Topbar handle
Bottom2” male thread/MPT
Ø 5-3/16" (132 mm)16" (406 mm)Side view · end views belowTopBottom
Top: bar handle
Bottom: 2” male thread/MPT
Drawn to scale from the listed diameter and length. Handles, threads and closed ends are drawn as symbols, not to scale. 50 sq ft media.

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Marquis Spas files this cartridge as 5CH-512 cartridge (OEM 20690), in the Marquis Spas (listed as Pacific Marquis in the Filbur catalog) group. Numbers on the row: OEM 20690, 370-0699; Unicel 5CH-512. 5-3/16" across, 16" long, top bar handle, bottom 2” male thread/MPT, 50 sq ft.

What the sources add about 20690: Marquis's own filter finder lists part 20690 as the threaded 50 sq ft filter for Crown Series spas from 2021, Elite models (Woodstock, Vegas, Hollywood, Broadway, Monaco Elite) from 2020, and the same Elite models in the 2018–2019 Celebrity Series. Two Marquis parts dealers describe 20690 as 5-3/16" x 16" with a handle top and 2" MPT thread, 50 sq ft, which matches Unicel's 5CH-512; they describe it as used on Celebrity Elite and V150 models rather than naming Crown. Marquis's 2026 Crown owner's manual describes a single 35 sq ft cartridge, which does not match the finder's 50 sq ft 20690 for Crown; see our Marquis model-year page.

Marquis Spas applications recorded for this cartridge: Marquis Crown Series, years 2021 and newer, listed by Marquis Spas filter finder (threaded 50 sq ft); Marquis Elite: Woodstock, Vegas, Hollywood, Broadway, Monaco Elite, years 2020 and newer, listed by Marquis Spas filter finder (threaded 50 sq ft); Marquis Celebrity Series Elite models: Woodstock, Vegas, Hollywood, Broadway, Monaco Elite, years 2018–2019, listed by Marquis Spas filter finder (threaded 50 sq ft).

Hold 5CH-512 next to C-5346 differs by Unicel C-5346, Pleatco PPM50TC, Filbur FC-3638, 14-1/8" long, top closed, bottom 1-5/8" / open, OEM 20044, note says Closed-top slip-on cartridge, old style. Marquis's own filter finder lists 20044 as the slip-on 50 sq ft filter for 1997–1999 Signature Series spas, which matches Unicel's C-5346 (5-3/16" x 14-1/8", closed top, 1-5/8" open bottom, 50 sq ft) and Filbur's FC-3638 of the same size. The second factory number still differs: Unicel lists 370-0236, while Filbur prints 370-217 for the same size.; 5CH-352 differs by Unicel 5CH-352, Pleatco PPM35SC-F2M, Filbur FC-0196, 12-1/2" long, 35 sq ft, OEM 20042, note says Pleatco 2023 lists OEM 20042, 370-0242 and 370-0243 for PPM35SC-F2M; Filbur lists OEM 370-0242 for FC-0196 and prints N/A in its Pleatco column..

Pleatco and Filbur do not have a number on this row. Search 20690 or the Marquis Spas part you pulled out of the spa.

Left blank on purpose: no Pleatco or Filbur equivalent found in either catalog; 2026 Crown owner's manual describes a 35 sq ft filter, not the finder's 50 sq ft 20690.

Pages checked for 20690: Unicel 2026 Replacement Guide on 5CH-512 (OEM cross reference (Marquis Spas section), PDF p.44 (printed p.40); spec table PDF p.10 (printed p.6)). Marquis Spas (manufacturer filter finder) on 5CH-512 (Filter Finder (series, model years, slip-on/threaded, sq ft, part number): Crown Series 2021 and newer, threaded 50, 20690; Elite 2020 and newer and Celebrity Series Elite 2018–2019, threaded 50, 20690). Canada Hot Tub Parts (Marquis parts dealer) on 5CH-512 (Marquis 20690: 5-3/16" x 16", handle top, 2" threaded MPT, 50 sq ft; for Celebrity Elite and V150 Select models). Hot Spring Supply (retailer) on 5CH-512 (Marquis Crown Collection 2021 threaded 50 sq ft filter 20690: 5-3/16" x 16", handle, 2" MPT; used on some Celebrity Elite and V150 models).

Hot tubs listed for this cartridge

The rest of the Marquis Spas model list is the Marquis Spas filter by model and year lookup.

Model / systemYearsListed by
Marquis Crown Series (threaded 50 sq ft)2021 and newerMarquis Spas filter finder
Marquis Elite: Woodstock, Vegas, Hollywood, Broadway, Monaco Elite (threaded 50 sq ft)2020 and newerMarquis Spas filter finder
Marquis Celebrity Series Elite models: Woodstock, Vegas, Hollywood, Broadway, Monaco Elite (threaded 50 sq ft)2018–2019Marquis Spas filter finder

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. Number formats: how Filbur, Unicel and Pleatco numbers compare.

Other Marquis Spas cartridges

All 9 Marquis Spas spa filters

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

Sources

Not in sources: no Pleatco or Filbur equivalent found in either catalog; 2026 Crown owner's manual describes a 35 sq ft filter, not the finder's 50 sq ft 20690.