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Caldera OEM 033016 spa filter (C-7451)
Listed for: Caldera (Watkins)
Fits Caldera OEM 033016 cited
Ø 7"L 10-3/4"50 sq ft| Unicel | C-7451 |
|---|---|
| Pleatco | PCD50 |
| Filbur | not sourced |
| Top | semi-circular handle |
| Bottom | 2” male slip fitting |
Retailer search links — see disclosure. Verify dimensions before ordering.
Source note: C-7350 can also be used
How to confirm this is your filter
Pull your current cartridge and measure it end to end, including any handle, and across the widest point of the pleats. This cartridge measures 7" in diameter and 10-3/4" long, with a semi-circular handle on top and a 2” male slip fitting on the bottom. The bottom fitting matters most: a cartridge with the right diameter but the wrong thread or open-end size will not seal in the filter housing, letting unfiltered water bypass the media.
The 50 sq ft rating describes the pleated media area. Caldera housings are designed around a particular cartridge, so choose a replacement with the same size and fittings rather than a larger area rating. Unicel C-7451 and Pleatco PCD50 are cross-referenced to each other in the Pleatco 2023 catalog, so either should fit the same housing.
Similar-diameter Caldera cartridges
- C-7350 cartridge (OEM 1019401) — 7" × 10-3/4"
- C-7375 cartridge (OEM 1019301) — 7" × 14-3/4"
- C-7479 cartridge (OEM 033017) — 7" × 14-3/4"
Sources
- Unicel 2026 Replacement Guide — OEM Cross Reference, PDF p.29; spec table PDF p.14 (PDF)
- Pleatco 2023 Catalog — Unicel-to-Pleatco cross reference, PDF p.43 (PDF)
Not in sources: no Filbur equivalent sourced; no model-year range in source.