Waterway Plastics OEM 817-0012 spa filter (6CH-942)

Front access, stacked lower

Replacement numbers

Unicel 6CH-942, Filbur FC-0361

Fits Waterway Plastics OEM 817-0012.

Diameter 6" (152 mm)Length 8-1/4" (210 mm)45 sq ft

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Unicel6CH-942
Pleatconot found in source (The set PWW100P3-SET (PDF p.33, cross-reference PDF p.47) names 817-0012 together with 817-0011. Not stored on this row.)
FilburFC-0361
Top1-3/4" (44 mm) open
Bottom1-1/2" SAE
Ø 6" (152 mm)8-1/4" (210 mm)Side view · end views belowTopBottom
Top: 1-3/4" (44 mm) open
Bottom: 1-1/2" SAE
Drawn to scale from the listed diameter and length and open-end sizes. Handles, threads and closed ends are drawn as symbols, not to scale. 45 sq ft media.

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Waterway Plastics files this cartridge as 6CH-942 cartridge (OEM 817-0012), in the Front access, stacked lower group. Numbers on the row: OEM 817-0012; Unicel 6CH-942; Filbur FC-0361. 6" across, 8-1/4" long, top 1-3/4" open, bottom 1-1/2" SAE, 45 sq ft.

What the sources add about 817-0012: Lower half of the stacked front-access pair. Top is 1-3/4" open so the upper cartridge's slip can enter it. Bottom is 1-1/2" SAE. Unicel says it must be used with 6CH-941. Waterway's table calls 817-0012 a 50 sq ft lower cartridge. The spec table prints 45 sq ft, stored here. Filbur's description says 40 and the Waterway column prints 80. Pleatco's PWW100P3-SET is the pair, not this cartridge alone.

6CH-942 (OEM 817-0012), Pleatco side: The set PWW100P3-SET (PDF p.33, cross-reference PDF p.47) names 817-0012 together with 817-0011. Not stored on this row..

817-0012, Filbur note: Waterway section PDF p.28: FC-0361, 6 x 8-1/4, 1-3/4" open top, 1-1/2" SAE bottom, OEM 817-0012, 6CH-942, sq ft column 80..

Hold 6CH-942 next to 6CH-940 differs by Unicel 6CH-940, Pleatco PWW50P3, Filbur FC-0359, top semi-circular handle, OEM 817-0050, note says Front-access cartridge. Waterway's Service Logic table (fetched 2026-11-09) calls 817-0050 a 50 sq ft, 6" x 8-1/4" F/A skimmer cartridge. Unicel's Waterway list prints the same 50 sq ft, and a second line at 100 sq ft with the note that two cartridges are used side by side. The spec table and Unicel's own product list print 6CH-940 at 45 sq ft, 225 pleats. The 45 stored here is the spec-table figure. Pleatco PWW50P3 is 6" x 7-5/8", 50 sq ft, and says two are required. Filbur FC-0359's sq ft column is 40.; 6CH-941 differs by Unicel 6CH-941, Filbur FC-0360, top semi-circular handle, bottom 1-3/4" male slip, OEM 817-0011, note says Upper half of the stacked front-access pair. Unicel says 6CH-941 must be used with 6CH-942. Waterway's table calls 817-0011 a 50 sq ft upper cartridge. The spec table prints 45 sq ft and 225 pleats, which is the figure stored here. The bottom is a 1-3/4" male slip, not the 1-1/2" SAE of 817-0050. Pleatco's live number is the pair, PWW100P3-SET, 6" x 16-1/2" and 100 sq ft, so it is not stored as the equivalent of this one cartridge. Filbur's description says 40 sq ft and the Waterway sq ft column prints 80..

Pleatco does not have a number on this row. Search 817-0012 or the Waterway Plastics part you pulled out of the spa.

Left blank on purpose: Same area split as 817-0011: 50, 45, or 40 per cartridge, and 80 in Filbur's Waterway column. The Pleatco set is 100 sq ft for both cartridges together..

Pages checked for 817-0012: Unicel 2026 Replacement Guide on 6CH-942 (Waterway list PDF p.64: 817-0012 = 6CH-942, 1-1/2" SAE, stacked with 817-0011. Spec table PDF p.12: 45 sq ft, 1-3/4" open top, must be used with 6CH-941.). Waterway Plastics Service Logic cartridge table on 6CH-942 (Fetched 2026-11-09: 817-0012, 50 sq ft lower cartridge (extension)). Pleatco 2023 Catalog on 6CH-942 (PWW100P3-SET spec, PDF p.33, includes OEM 817-0012). Filbur Catalog & Reference Guide on 6CH-942 (Waterway section PDF p.28: FC-0361, OEM 817-0012, 6CH-942).

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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.

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Sources

Not in sources: Same area split as 817-0011: 50, 45, or 40 per cartridge, and 80 in Filbur's Waterway column. The Pleatco set is 100 sq ft for both cartridges together..