Saratoga Spas OEM 74408-99 spa filter (4CH-950)

Saratoga Spas

Replacement numbers

Unicel 4CH-950, Filbur FC-0173

Fits Saratoga Spas OEM 74408-99.

Diameter 4-5/8" (117 mm)Length 12" (305 mm)25 sq ft

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Unicel4CH-950
Pleatconot found in source (Deactivated list: PDO-UF25 replacement N/A. No 4CH-950 line found in the 2023 Unicel cross-reference.)
FilburFC-0173
Topsemi-circular handle
Bottom1-1/4" SAE
Ø 4-5/8" (117 mm)12" (305 mm)Side view · end views belowTopBottom
Top: semi-circular handle
Bottom: 1-1/4" SAE
Drawn to scale from the listed diameter and length. Handles, threads and closed ends are drawn as symbols, not to scale. 25 sq ft media.

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Saratoga Spas files this cartridge as 4CH-950 cartridge (OEM 74408-99), in the Saratoga Spas group. Numbers on the row: OEM 74408-99; Unicel 4CH-950; Filbur FC-0173. 4-5/8" across, 12" long, top semi-circular handle, bottom 1-1/4" SAE, 25 sq ft.

74408-99 carries this note from the catalogs: 1-1/4" SAE, not MPT. Unicel's Saratoga line: OEM 74408-99, 4-5/8" x 12", 25 sq ft. Spec table: 139 pleats, and the description also names Dimension One. Filbur FC-0173 is 11-7/8" long. The Saratoga section's sq ft column is 27; the size table says 25 sq ft. The Pleatco cell PDO-UF25P2 is deactivated with replacement N/A, so no Pleatco number is stored. Dimension One's OEM for this Unicel number is 1561-04. The 25 and 12" stored here are Unicel's.

4CH-950 (OEM 74408-99), Pleatco side: Deactivated list: PDO-UF25 replacement N/A. No 4CH-950 line found in the 2023 Unicel cross-reference..

74408-99, Filbur note: Saratoga section PDF p.25: FC-0173, 4-5/8" x 11-7/8", 1-1/4" SAE, PDO-UF25P2, 4CH-950, 27 sq ft. Size table: '25 sq. ft. Top Load,' column 25..

4CH-950 is easy to confuse on the Saratoga Spas table. 4CH-30 differs by Unicel 4CH-30, Filbur FC-0141, 11-7/8" long, top molded cone handle, bottom 1-1/2" MPT, 30 sq ft, OEM 74407-98, note says Longest of the Saratoga 1-1/2" MPT cartridges. Unicel: 4-5/8" x 11-7/8", 158 pleats, 4 oz media, 30 sq ft, OEM 74407-98. Filbur FC-0141 is the same length and prints 27 sq ft. The Pleatco cell on that Filbur row, PTL25P-4, is on Pleatco's deactivated list and is sent to PSG27.5P4. PSG27.5P4's own spec is 4-3/4" x 11-3/8", 28 sq ft, 'Saratoga Spas Circulation Pump,' and it does not print 74407-98 or 4CH-30, so it is not stored as the equivalent. The 2023 cross-reference has no 4CH-30 line. The 30 stored here is Unicel's.. 4CH-24 differs by Unicel 4CH-24, Pleatco PGS25P4, Filbur FC-0131, 9-3/4" long, top molded cone handle, bottom 1-1/2" MPT, OEM 20254-238, note says 1-1/2" MPT, 4-5/8" x 9-3/4", 25 sq ft. Unicel's spec table gives 173 pleats. Pleatco PGS25P4 and Filbur FC-0131 print the same size and 25 sq ft for OEM 20254-238. This is the Saratoga cartridge the three catalogs agree on..

Pleatco does not have a number on this row. Search 74408-99 or the Saratoga Spas part you pulled out of the spa.

Left blank on purpose: Length 12" (Unicel) vs 11-7/8" (Filbur). Filbur Saratoga section 27 sq ft vs Unicel and Filbur's size table at 25. Pleatco cell deactivated, replacement N/A..

Source locations for this Saratoga Spas row: Unicel 2026 Replacement Guide on 4CH-950 (Saratoga list PDF p.55: 74408-99 = 4CH-950, 4-5/8" x 12", 25 sq ft, 1-1/4" SAE. Spec table PDF p.8: 139 pleats, 25 sq ft. Price index PDF p.88: 25 sq ft.). Filbur Catalog & Reference Guide on 4CH-950 (Saratoga section PDF p.25: FC-0173 at 27 sq ft and 11-7/8". Size table: 25 sq ft.). Pleatco 2023 Catalog on 4CH-950 (Deactivated list: PDO-UF25 replacement N/A).

If you know the Saratoga Spas model and not the part number, use the Saratoga 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. Number formats: how Filbur, Unicel and Pleatco numbers compare.

The same 4CH-950 number is also on the Dimension One Spas page.

Other Saratoga Spas cartridges

All 6 Saratoga 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

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Sources

Not in sources: Length 12" (Unicel) vs 11-7/8" (Filbur). Filbur Saratoga section 27 sq ft vs Unicel and Filbur's size table at 25. Pleatco cell deactivated, replacement N/A..