Opens an Amazon search for this part number, not one listing we pre-checked.
Freeflow Spas spa filter (4CH-23)
Freeflow Spas
Replacement numbers
Unicel 4CH-23, Pleatco PFF25TC-P4
Fits Freeflow Spas.
Diameter 4-15/16" (125 mm)Length 6-5/8" (168 mm)25 sq ft2 models listedSearch this part on Amazon
Disclosure: we may earn a commission from qualifying purchases made through retailer links on this site, at no extra cost to you. As an Amazon Associate I earn from qualifying purchases. Search on Amazon opens an Amazon search for this part number, not one listing we pre-checked. These are affiliate links. Product photos are omitted unless Amazon supplied one through the Product Advertising API or a SiteStripe image link. Verify dimensions before ordering. Each “Check price on Amazon” button opens a specific listing whose title we checked. The line under the name repeats only that title. See our affiliate disclosure.
| Unicel | 4CH-23 |
|---|---|
| Pleatco | PFF25TC-P4 (Unicel cross-reference PDF p.47: 4CH-23 = PFF25TC-P4. Spec table PDF p.31: 4-5/8" x 6-5/8", closed, 1-1/2" MPT, 3 oz, 25 sq ft, Lagas, TLX, RLX, FF-100, Claro. Application index PDF p.27: Lagas TLX, RLX.) |
| Filbur | FC-2400 |
| Top | closed |
| 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.
Freeflow Spas is the group name on the Freeflow Spas row 4CH-23 cartridge (closed top). Match these numbers: Unicel 4CH-23; Pleatco PFF25TC-P4; Filbur FC-2400. 4-15/16" across, 6-5/8" long, top closed, bottom 1-1/2” male thread/MPT, 25 sq ft.
Catalog note for PFF25TC-P4: Unicel's spec table assigns the closed-top 4CH-23 to Freeflow CLX: 4-15/16" x 6-5/8", 212 pleats, 3 oz, 25 sq ft, 1-1/2" MPT. The Freeflow model list agrees. Filbur and Pleatco agree that 4CH-23 / FC-2400 / PFF25TC-P4 is the closed cartridge, and they assign it to TLX and RLX instead of CLX. Pleatco also names Lagas, FF-100 and Claro. Pleatco's outside diameter is 4-5/8".
4CH-23 (OEM 4CH-23 cartridge (closed top)), Pleatco side: Unicel cross-reference PDF p.47: 4CH-23 = PFF25TC-P4. Spec table PDF p.31: 4-5/8" x 6-5/8", closed, 1-1/2" MPT, 3 oz, 25 sq ft, Lagas, TLX, RLX, FF-100, Claro. Application index PDF p.27: Lagas TLX, RLX..
PFF25TC-P4, Filbur note: Dimensional listing PDF p.9: FC-2400, 4-15/16" x 6-5/8", closed, 1-1/2" MPT, Freeflo 25, TLX, PFF25TC-P4, 4CH-23, 25 sq ft. Freedom Spas section PDF p.18 (printed p.35): TLX, RLX, FF-100..
Freeflow Spas applications recorded for this cartridge: Freeflow CLX, no year range printed, listed by Unicel 2026 Replacement Guide (Unicel spec table and model list: closed top, 4CH-23); Freeflow TLX and RLX, no year range printed, listed by Filbur Catalog & Reference Guide (Filbur FC-2400, closed top, also numbered FF-100. Pleatco PFF25TC-P4 names Lagas, TLX, RLX, FF-100 and Claro.).
Hold 4CH-23 next to 4CH-22 differs by Unicel 4CH-22, Pleatco PFF25W-P4, Filbur FC-2399, top 2-1/8" / open, note says Unicel's spec table and Freeflow model list assign the open-top 4CH-22 to TLX and RLX: 4-15/16" x 6-5/8", 212 pleats, 3 oz, 25 sq ft, 1-1/2" MPT. Filbur's size table and its Freedom Spas section assign that same open 4CH-22 / FC-2399 to CLX (and FF-150) and print Pleatco PFF25P4. Pleatco's own Unicel cross-reference prints 4CH-22 = PFF25W-P4, which Pleatco sizes at 5" x 6-5/8" for Lagas and does not name TLX, RLX or CLX. The dimension on this row is Unicel's.; 5CH-45 differs by Unicel 5CH-45, Pleatco PFF50P4, Filbur FC-2401, 5-5/16" diameter, 10" long, top 2-1/8" / open, 45 sq ft, note says Unicel's spec table prints 5CH-45 for Freeflow Legend: 5-5/16" x 10", open 2-1/8", 1-1/2" MPT, 225 pleats, 3 oz, 45 sq ft. The Freeflow model list puts Legend and Passport on that row. Passport is not in the spec-table model cell, and Filbur and Pleatco do not name Passport. Pleatco PFF50P4 is 50 sq ft. Filbur's size table is 5-5/16" and 45 sq ft with Pleatco cell PFF50P; Filbur's Freedom Spas section prints the diameter as 5-1/4"..
Left blank on purpose: Unicel model is CLX; Filbur and Pleatco models are TLX and RLX (plus Lagas, FF-100, Claro). Diameter 4-15/16" vs Pleatco 4-5/8". No Freeflow OEM number in Unicel. FF-100 is Filbur/Pleatco only..
Where those figures are printed: Unicel 2026 Replacement Guide on 4CH-23 (Freeflow model list, PDF p.35 (printed p.31): CLX = 4CH-23; spec table PDF p.8 (printed p.4): closed top, 212 pleats, 3 oz, 25 sq ft, model cell CLX). Pleatco 2023 Catalog on 4CH-23 (Unicel cross-reference PDF p.47: 4CH-23 = PFF25TC-P4. Spec table PDF p.31 and application index PDF p.27: closed cartridge for TLX and RLX). Filbur Catalog & Reference Guide on 4CH-23 (Dimensional listing PDF p.9 and Freedom Spas section PDF p.18 (printed p.35): FC-2400 closed, TLX/RLX, FF-100, 4CH-23).
Hot tubs listed for this cartridge
The rest of the Freeflow Spas model list is the Freeflow Spas filter by model and year lookup.
| Model / system | Years | Listed by |
|---|---|---|
| Freeflow CLX (Unicel spec table and model list: closed top, 4CH-23) | not given | Unicel 2026 Replacement Guide |
| Freeflow TLX and RLX (Filbur FC-2400, closed top, also numbered FF-100. Pleatco PFF25TC-P4 names Lagas, TLX, RLX, FF-100 and Claro.) | not given | Filbur Catalog & Reference Guide |
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.
Other Freeflow Spas cartridges
- 4CH-22 cartridge (open top), 4-15/16" (125 mm) × 6-5/8" (168 mm)
- 5CH-45 cartridge (Legend), 5-5/16" (135 mm) × 10" (254 mm)
All 3 Freeflow Spas spa filters
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.
Search this part on Amazon Opens an Amazon search for this part number, not one listing we pre-checked.
Sources
- Unicel 2026 Replacement Guide: Freeflow model list, PDF p.35 (printed p.31): CLX = 4CH-23; spec table PDF p.8 (printed p.4): closed top, 212 pleats, 3 oz, 25 sq ft, model cell CLX (PDF)
- Pleatco 2023 Catalog: Unicel cross-reference PDF p.47: 4CH-23 = PFF25TC-P4. Spec table PDF p.31 and application index PDF p.27: closed cartridge for TLX and RLX (PDF)
- Filbur Catalog & Reference Guide: Dimensional listing PDF p.9 and Freedom Spas section PDF p.18 (printed p.35): FC-2400 closed, TLX/RLX, FF-100, 4CH-23 (PDF)
Not in sources: Unicel model is CLX; Filbur and Pleatco models are TLX and RLX (plus Lagas, FF-100, Claro). Diameter 4-15/16" vs Pleatco 4-5/8". No Freeflow OEM number in Unicel. FF-100 is Filbur/Pleatco only..