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C-4970 spa filter equivalents
Part number C-4970 appears in 1 cross-reference row 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.
Waterway Plastics C-4970 cartridge (OEM 817-7500), 4-15/16" (125 mm) × 23-5/8" (600 mm), 75 sq ft. Unicel C-4970, Pleatco not listed.
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| OEM | 817-7500 |
|---|---|
| Unicel | C-4970 |
| Pleatco | not listed |
| Filbur | FC-2930 |
| Size | 4-15/16" (125 mm) × 23-5/8" (600 mm), 75 sq ft |
Sources
- Unicel 2026 Replacement Guide: Waterway list PDF p.64: 817-7500 = C-4970, 75 sq ft, 4-15/16" x 23-5/8", discontinued, use C-4995. Spec table PDF p.9: 178 pleats, same discontinued note. (PDF)
- Waterway Plastics Service Logic cartridge table: Fetched 2026-11-09: 817-7500 still listed, 75 sq ft, in-line top-load (web page)
- Pleatco 2023 Catalog: Deactivated list PDF p.21: PCAL75 replacement PCAL100 (PDF)
- Filbur Catalog & Reference Guide: Waterway section PDF p.28: FC-2930, OEM 817-7500, C-4970, 75 sq ft (PDF)
Not in sources: Unicel says to stop using this number. Waterway's table and Filbur still list it at 75 sq ft. The replacement Unicel names is a different area..
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