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.
Hot Spot OEM 1019301 spa filter (C-7375)
Hot Spot (Hot Spring family)
Replacement numbers
Unicel C-7375, Pleatco PCD75N
Fits Hot Spot OEM 1019301, 73531.
Diameter 7" (178 mm)Length 14-3/4" (375 mm)75 sq ft1 model listedUnicel C-7375
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| Unicel | C-7375 |
|---|---|
| Pleatco | PCD75N |
| Filbur | FC-3964 |
| Top | semi-circular handle |
| Bottom | 2-11/16" (68 mm) / open |
Bottom: 2-11/16" (68 mm) / open
Drawn to scale from the listed diameter and length and open-end sizes. Handles, threads and closed ends are drawn as symbols, not to scale. 75 sq ft media.
Hot Spot (Hot Spring family) is the group name on the Hot Spot row C-7375 cartridge (OEM 1019301). Match these numbers: OEM 1019301, 73531; Unicel C-7375; Pleatco PCD75N; Filbur FC-3964. 7" across, 14-3/4" long, top semi-circular handle, bottom 2-11/16" / open, 75 sq ft.
What the sources add about 1019301: Unicel lists these OEM numbers under Caldera Spas; the Hot Spot Mallorca fitment is from Leisure Time Inc.; Leisure Time Inc.: For a 2004 Hawaiian HAA or a 2024 Makena, check the spa serial number before ordering.
Hot tubs named for 1019301: Hot Spot Mallorca, years 2003–2009, listed by Leisure Time Inc. dealer listing.
Hold C-7375 next to C-7350 differs by Unicel C-7350, Pleatco PCD50N, Filbur FC-3963, 10-3/4" long, 50 sq ft, OEM 1019401, note says Unicel lists these OEM numbers under Caldera Spas; the Hot Spot Sorrento fitment is from Leisure Time Inc.; Leisure Time Inc.: For a 2024 Makena, confirm the spa serial number before ordering. Other Makena years use a different cartridge.; C-6430 differs by Unicel C-6430, Pleatco PWK30-4, Filbur FC-3915, 6" diameter, 10-1/2" long, top 1-15/16" / open, bottom 1-15/16" / open, 30 sq ft, OEM 31489, note says Unicel lists these OEM numbers under Hot Springs Spas and directs Hot Spot owners there; Hot Spot model fitment is from Leisure Time Inc.; Leisure Time Inc.: Use this pleated cartridge only where the spa specifies 71825 or its listed equivalent. Models requiring Tri-X cartridges must use the appropriate Tri-X filter.; Leisure Time Inc.: Replaces compatible 71825 or 31489 pleated cartridges. Models requiring Tri-X cartridges must use the appropriate Tri-X filter. Unicel's 2026 price list (not its spec table, which still prints C-6430 with 4 oz media) says "C-6430 USE C-6430AM", the antimicrobial version (30 sq ft, Watkins replacement)..
Where those figures are printed: Unicel 2026 Replacement Guide on C-7375 (OEM cross reference (Hot Springs Spas section), PDF p.30 (printed p.26); spec table PDF p.16 (printed p.12)). Pleatco 2023 Catalog on C-7375 (Unicel-to-Pleatco cross reference, PDF p.47). Filbur Catalog & Reference Guide on C-7375 (Product by Pool/Spa Manufacturer (OEM), Caldera, printed p.30 (PDF p.16)). Leisure Time Inc. (Hot Spring/Caldera dealer) on C-7375 (Compatibility section: model and model-year list).
Hot tubs listed for this cartridge
| Model / system | Years | Listed by |
|---|---|---|
| Hot Spot Mallorca | 2003–2009 | Leisure Time Inc. dealer listing |
Other Hot Spot models and years are in the Hot Spot section of the Hot Spring 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: Hot Spring filter sizes by collection. Number formats: how Filbur, Unicel and Pleatco numbers compare.
The same C-7375 number is also on the Caldera page.
Other Hot Spot cartridges
- C-7350 cartridge (OEM 1019401), 7" (178 mm) × 10-3/4" (273 mm)
- C-6430 cartridge (OEM 31489), 6" (152 mm) × 10-1/2" (267 mm)
- C-4326 cartridge (OEM 33521), 4-15/16" (125 mm) × 13-5/16" (338 mm)
- C-8465 cartridge (OEM 31114), 8-1/2" (216 mm) × 10-1/2" (267 mm)
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
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
-
Leisure Time O Filter Clean Cartridge Cleaner Listing title: cartridge cleaner, 32 fl oz.
-
SpaGuard Filter Cleaner Listing title: filter cleaner for spas and hot tubs, 1 quart.
-
AquaChek SPA 6-in-1 Test Strips Listing title: reads total bromine, total chlorine, free chlorine, pH, total alkalinity and total hardness.
Unicel C-7375 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.
Sources
- Unicel 2026 Replacement Guide: OEM cross reference (Hot Springs Spas section), PDF p.30 (printed p.26); spec table PDF p.16 (printed p.12) (PDF)
- Pleatco 2023 Catalog: Unicel-to-Pleatco cross reference, PDF p.47 (PDF)
- Filbur Catalog & Reference Guide: Product by Pool/Spa Manufacturer (OEM), Caldera, printed p.30 (PDF p.16) (PDF)
- Leisure Time Inc. (Hot Spring/Caldera dealer): Compatibility section: model and model-year list (web page)