4-15/16" × 6-5/8"
Freeflow Spas spa filters
Freeflow’s short filters are one 4-15/16" × 6-5/8" body with a 1-1/2" MPT bottom. Unicel’s spec table makes TLX and RLX the open-top 4CH-22 and CLX the closed-top 4CH-23. Filbur and Pleatco swap those model names and keep the same tops on the same Unicel numbers.
Legend is the longer cartridge, 5CH-45. Unicel and Filbur rate it at 45 sq ft and Pleatco at 50. Passport is named only on Unicel’s model list. The conflict table is on the Freeflow filter page. Filbur files these model names under a Freedom Spas heading; Unicel does not.
This page lists 3 Freeflow Spas replacement cartridges from the Unicel 2026 Replacement Guide, the Pleatco 2023 catalog and the Filbur catalog, plus model and model-year fitment for 3 of them (3 hot tub models in total). 3 have a Filbur number. Find your spa filter by the OEM part number on the end cap, or measure it and compare sizes below.
Clean and replace intervals for one cartridge on this list, plus the cross-reference numbers and a buy link: filter replacement schedule and reorder.
- 4CH-224CH-22, 4-15/16" (125 mm) × 6-5/8" (168 mm)See replacement
- 4CH-234CH-23, 4-15/16" (125 mm) × 6-5/8" (168 mm)See replacement
- 5CH-455CH-45, 5-5/16" (135 mm) × 10" (254 mm)See replacement
| Cartridge | Unicel | Pleatco | Filbur | Size | Fits | Status |
|---|---|---|---|---|---|---|
| 4CH-22 (Freeflow Spas) | 4CH-22 | PFF25W-P4 | FC-2399 | 4-15/16" (125 mm) × 6-5/8" (168 mm), 25 sq ft | 2 models | verified |
| 4CH-23 (Freeflow Spas) | 4CH-23 | PFF25TC-P4 | FC-2400 | 4-15/16" (125 mm) × 6-5/8" (168 mm), 25 sq ft | 2 models | verified |
| 5CH-45 (Freeflow Spas) | 5CH-45 | PFF50P4 | FC-2401 | 5-5/16" (135 mm) × 10" (254 mm), 45 sq ft | 2 models | verified |
Know your model but not the part number? See Freeflow Spas filter by model and year.
Guides that apply to Freeflow Spas
- Freedom Spas filter by model, the other catalog heading
- Open-end vs threaded hot tub filters
- How Filbur, Unicel and Pleatco numbers compare
- How to find your spa filter size
- How to install a cartridge
- All guides
Search Freeflow Spas part numbers on Amazon
Each button opens an Amazon search for that part number. The cartridge page is where the cited size and fittings are. Match those before you buy.
Part numbers from this table
-
4CH-22 cartridge (open top) -
4CH-23 cartridge (closed top) 4-15/16" × 6-5/8"
-
5CH-45 cartridge (Legend) 5-5/16" × 10"
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. Amazon links on this page go to Amazon.com and are affiliate links; they never change what we write, and the list is not ranked by commission. Each “Search on Amazon” button opens an Amazon search for the part or product name shown, not a single listing we pre-checked. Check size, quantity and your spa maker’s guidance before you buy. See our affiliate disclosure.
Model-year fitment comes only from the sources named on each cartridge page. Where no source lists models or years, the page says so.