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.
Softub OEM 90-802 spa filter (6CH-25)
Softub (also listed for Leisure Bay by Pleatco)
Replacement numbers
Unicel 6CH-25, Pleatco PTL20W-SV-P4
Fits Softub OEM 90-802.
Diameter 6" (152 mm)Length 5-1/2" (140 mm)25 sq ft1 model listedUnicel 6CH-25
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| Unicel | 6CH-25 |
|---|---|
| Pleatco | PTL20W-SV-P4 |
| Filbur | FC-0305 |
| Top | semi-circular handle |
| Bottom | 1-1/2” male thread/MPT |
Bottom: 1-1/2” male thread/MPT
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.
For Softub, 6CH-25 cartridge (OEM 90-802) sits in Softub (also listed for Leisure Bay by Pleatco). The cross-reference prints OEM 90-802; Unicel 6CH-25; Pleatco PTL20W-SV-P4; Filbur FC-0305. 6" across, 5-1/2" long, top semi-circular handle, bottom 1-1/2” male thread/MPT, 25 sq ft.
Catalog note for 90-802: Unicel rates 6CH-25 at 25 sq ft; Pleatco rates PTL20W-SV-P4 (same OEM 90-802, 6" x 5-1/2", handle, 1-1/2" MPT) at 20 sq ft. The Filbur catalog lists FC-0305 against the same OEM 90-802 at 6" x 5-1/2", handle top, 1-1/2" MPT, 25 sq ft, and cross-references it to PTL20W-SV-P-4 and 6CH-25. Size, OEM number and fitting agree across all three catalogs.
90-802, Filbur note: Filbur lists FC-0305 under Softsider Spas with the same OEM 90-802 (printed p.50, PDF p.26); Filbur does not name Softub.
Model list attached to 6CH-25 cartridge (OEM 90-802): Softub; Leisure Bay (6 x 5-1/2, TSC), no year range printed, listed by Pleatco 2023 Catalog (Pleatco spec table, OEM 90-802).
Left blank on purpose: sq ft rating differs between Unicel/Filbur (25) and Pleatco (20); Filbur files OEM 90-802 under Softsider Spas rather than Softub; no model-year fitment in sources.
Where those figures are printed: Unicel 2026 Replacement Guide on 6CH-25 (OEM cross reference (Softub section), PDF p.55 (printed p.51); spec table PDF p.12 (printed p.8)). Pleatco 2023 Catalog on 6CH-25 (Unicel-to-Pleatco cross reference, PDF p.47 (6CH-25 = PTL20W-SV-P4); spec table PDF p.33 (Softub; Leisure Bay; 6 x 5-1/2, OEM 90-802)). Filbur Catalog & Reference Guide on 6CH-25 (Product by Pool/Spa Manufacturer (OEM), Softsider Spas (continued), printed p.50 (PDF p.26): FC-0305, 6 x 5-1/2, handle, OEM 90-802, PTL20W-SV-P-4, 6CH-25, 25 sq ft).
Hot tubs listed for this cartridge
The rest of the Softub model list is the Softub filter by model and year lookup.
| Model / system | Years | Listed by |
|---|---|---|
| Softub; Leisure Bay (6 x 5-1/2, TSC) (Pleatco spec table, OEM 90-802) | not given | Pleatco 2023 Catalog |
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.
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
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Leisure Time O Filter Clean Cartridge Cleaner Listing title: cartridge cleaner, 32 fl oz.
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SpaGuard Filter Cleaner Listing title: filter cleaner for spas and hot tubs, 1 quart.
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AquaChek SPA 6-in-1 Test Strips Listing title: reads total bromine, total chlorine, free chlorine, pH, total alkalinity and total hardness.
Unicel 6CH-25 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 (Softub section), PDF p.55 (printed p.51); spec table PDF p.12 (printed p.8) (PDF)
- Pleatco 2023 Catalog: Unicel-to-Pleatco cross reference, PDF p.47 (6CH-25 = PTL20W-SV-P4); spec table PDF p.33 (Softub; Leisure Bay; 6 x 5-1/2, OEM 90-802) (PDF)
- Filbur Catalog & Reference Guide: Product by Pool/Spa Manufacturer (OEM), Softsider Spas (continued), printed p.50 (PDF p.26): FC-0305, 6 x 5-1/2, handle, OEM 90-802, PTL20W-SV-P-4, 6CH-25, 25 sq ft (PDF)
Not in sources: sq ft rating differs between Unicel/Filbur (25) and Pleatco (20); Filbur files OEM 90-802 under Softsider Spas rather than Softub; no model-year fitment in sources.