Listing we opened and checked. Match the diameter, length and both fittings on this page before you order. The price is on Amazon; we do not print one.
4CH-935 spa filter equivalents
Part number 4CH-935 appears in 3 cross-reference rows below. Each row lists the OEM, Unicel and Pleatco numbers that the source documents treat as interchangeable, plus the cartridge size so you can confirm against your old filter.
The same numbers, on one page, are in the cross-reference lookup. A schedule for this part number, and the buy link, are on the replacement schedule and reorder page. Published intervals by brand are in the replace and clean calculator.
Master Spas 4CH-935 cartridge, 4-15/16" (125 mm) × 9-1/4" (235 mm), 35 sq ft. Unicel 4CH-935, Pleatco PWW35L.
Unicel 4CH-935
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| OEM | |
|---|---|
| Unicel | 4CH-935 |
| Pleatco | PWW35L |
| Filbur | not listed |
| Size | 4-15/16" (125 mm) × 9-1/4" (235 mm), 35 sq ft |
Sources
- Unicel 2026 Replacement Guide: OEM cross reference (Master Spas section), PDF p.45 (printed p.41); spec table PDF p.8 (printed p.4) (PDF)
- Pleatco 2023 Catalog: Unicel-to-Pleatco cross reference, PDF p.47 (PDF)
Not in sources: no Filbur equivalent found in Filbur catalog; no model/model-year fitment in sources; Unicel lists no OEM part number for this brand entry.
Full details → · All Master Spas spa filters · Which fitting you need · How to install it
Nordic Hot Tubs 4CH-935 cartridge, 4-15/16" (125 mm) × 9-1/4" (235 mm), 35 sq ft. Unicel 4CH-935, Pleatco PWW35L.
Unicel 4CH-935 Listing we opened and checked. Match the diameter, length and both fittings on this page before you order. The price is on Amazon; we do not print one.
| OEM | CARTRIDGE-T35 |
|---|---|
| Unicel | 4CH-935 |
| Pleatco | PWW35L |
| Filbur | not listed |
| Size | 4-15/16" (125 mm) × 9-1/4" (235 mm), 35 sq ft |
Sources
- Unicel 2026 Replacement Guide: OEM cross reference (Nordic Hot Tubs section), PDF p.46 (printed p.42); spec table PDF p.8 (printed p.4) (PDF)
- Pleatco 2023 Catalog: Unicel-to-Pleatco cross reference, PDF p.47 (4CH-935 = PWW35L) (PDF)
- Nordic Hot Tubs filter chart (2023): CARTRIDGE-T35 row: Unicel 4CH-935, Pleatco PWW35L, Filbur NA, Waterway 817-4035; model list (PDF)
- Nordic Hot Tubs owner's manual (01.2024): Filter Quick Reference by Model, p.22: CARTRIDGE-T35, 9-1/4" x 4-15/16", handle top, 2" SAE female thread, 35 sq ft (PDF)
Not in sources: no Filbur equivalent (Nordic's chart prints NA); Pleatco's spec table prints PWW35L as 5" x 8-1/2" with a 1-1/2" bottom, not 4-15/16" x 9-1/4"; Nordic's chart has no Crown entry for 2008-2014.
Full details → · All Nordic Hot Tubs spa filters · Which fitting you need · How to install it
Waterway Plastics 4CH-935 cartridge (OEM 817-4035), 4-15/16" (125 mm) × 9-1/4" (235 mm), 35 sq ft. Unicel 4CH-935, Pleatco PWW35L.
Unicel 4CH-935 Listing we opened and checked. Match the diameter, length and both fittings on this page before you order. The price is on Amazon; we do not print one.
| OEM | 817-4035 |
|---|---|
| Unicel | 4CH-935 |
| Pleatco | PWW35L |
| Filbur | FC-0170 |
| Size | 4-15/16" (125 mm) × 9-1/4" (235 mm), 35 sq ft |
Sources
- Unicel 2026 Replacement Guide: Waterway list PDF p.64: 817-4035 = 4CH-935, 4-15/16" x 9-1/4", 35 sq ft. Spec table PDF p.8: 219 pleats, 2" female SAE, standpipe note. (PDF)
- Waterway Plastics Service Logic cartridge table: Fetched 2026-11-09: 817-4035, 35 sq ft, 4-15/16" x 9-1/4", SAE thread (web page)
- Pleatco 2023 Catalog: Spec table PDF p.32: PWW35L, OEM 817-4035, 5" x 8-1/2", 35 sq ft. Cross-reference PDF p.47: 4CH-935 = PWW35L. (PDF)
- Filbur Catalog & Reference Guide: Waterway section PDF p.28: FC-0170, OEM 817-4035, 30 sq ft, Unicel N/A (PDF)
Not in sources: Length 9-1/4" (Unicel, Waterway, Filbur) vs 8-1/2" (Pleatco). Area 35 vs Filbur's 30. Filbur prints no Unicel number on the 817-4035 row. Thread 2" female SAE (Unicel) vs 1-1/2" female SAE (Pleatco)..
Full details → · All Waterway Plastics spa filters · Which fitting you need · How to install it