Master Spas OEM PMA-R1 spa filter (6CH-352)

Master Spas Eco-Pur (6" OD)

Replacement numbers

Unicel 6CH-352, Pleatco PAS40-F2M

Fits Master Spas OEM PMA-R1.

Diameter 6" (152 mm)Length 8" (203 mm)35 sq ft

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Unicel6CH-352
PleatcoPAS40-F2M
FilburFC-0312
Topsemi-circular handle
Bottom2” male thread/MPT
Ø 6" (152 mm)8" (203 mm)Side view · end views belowTopBottom
Top: semi-circular 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. 35 sq ft media.

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Master Spas Eco-Pur (6" OD) is the group name on the Master Spas row 6CH-352 cartridge (OEM PMA-R1). Match these numbers: OEM PMA-R1; Unicel 6CH-352; Pleatco PAS40-F2M; Filbur FC-0312. 6" across, 8" long, top semi-circular handle, bottom 2” male thread/MPT, 35 sq ft.

What the sources add about PMA-R1: Unicel: must remove black stand pipe. Filbur cross-references 6CH-352 to FC-0312 but lists FC-0312 at 6" x 7".

Before ordering 6CH-352, compare it with 6CH-940 differs by Unicel 6CH-940, Pleatco PWW50P3, Filbur FC-0359, 8-1/4" long, bottom injection molded 1-1/2" SAE thread, 45 sq ft, no OEM number, note says Unicel: for use in Master Spas swim spas; and 6CH-402 differs by Unicel 6CH-402, Pleatco PMA40L-F2M, Filbur FC-0317, 9-1/2" long, 40 sq ft, OEM PMA40L-F2M, note says Unicel prints PMA40L-F2M (a Pleatco number) in its OEM column; Pleatco lists Master Spas Twilight OEM X268365 for PMA40L-F2M. Unicel: must remove black stand pipe.

Left blank on purpose: no model/model-year fitment in sources.

Pages checked for PMA-R1: Unicel 2026 Replacement Guide on 6CH-352 (OEM cross reference (Master Spas section), PDF p.45 (printed p.41); spec table PDF p.12 (printed p.8)). Pleatco 2023 Catalog on 6CH-352 (Unicel-to-Pleatco cross reference, PDF p.47). Filbur Catalog & Reference Guide on 6CH-352 (Unicel-to-Filbur reverse cross reference, printed p.66 (PDF p.34)).

If you know the Master Spas model and not the part number, use the Master Spas filter by model and year lookup.

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. Brand notes: Master Spas Eco-Pur filters. Number formats: how Filbur, Unicel and Pleatco numbers compare.

Other Master Spas cartridges

All 13 Master Spas spa filters

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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 model/model-year fitment in sources.