6" × 8-1/4"
Waterway Plastics spa filters
Waterway’s spa cartridges are named by housing, not by hot-tub model. The front-access skim filter is 817-0050, one cartridge or two side by side. A different front-access well stacks 817-0011 on 817-0012. The Teleweir cartridges, 817-4025, 817-4035, and 817-4050, are a female-SAE fitting, and the two long ones share a length.
Waterway’s own table rates 817-0050 at 50 sq ft. Unicel’s spec table prints 45, and Filbur’s column prints 40. Those figures, the discontinued 817-7500, and the teal end-cap note for 2003–2006 are on the Waterway filter page.
This page lists 12 Waterway Plastics replacement cartridges from the Unicel 2026 Replacement Guide, the Pleatco 2023 catalog, the Filbur catalog and manufacturer and retailer pages. 12 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.
- 6CH-9406CH-940, 6" (152 mm) × 8-1/4" (210 mm)See replacement
- 6CH-9416CH-941, 6" (152 mm) × 8-1/4" (210 mm)See replacement
- 6CH-9426CH-942, 6" (152 mm) × 8-1/4" (210 mm)See replacement
- 4CH-9264CH-926, 4-15/16" (125 mm) × 13-1/2" (343 mm)See replacement
- 4CH-9354CH-935, 4-15/16" (125 mm) × 9-1/4" (235 mm)See replacement
- 4CH-9494CH-949, 4-15/16" (125 mm) × 13-1/2" (343 mm)See replacement
- C-4310C-4310, 4-1/4" (108 mm) × 4" (102 mm)See replacement
- C-4326C-4326, 4-15/16" (125 mm) × 13-5/16" (338 mm)See replacement
- C-4950C-4950, 4-15/16" (125 mm) × 13-5/16" (338 mm)See replacement
- C-4970C-4970, 4-15/16" (125 mm) × 23-5/8" (600 mm)See replacement
- C-4995C-4995, 4-15/16" (125 mm) × 23-5/8" (600 mm)See replacement
- C-6375C-6375, 6-9/16" (167 mm) × 13-5/16" (338 mm)See replacement
| Cartridge | Unicel | Pleatco | Filbur | Size | Fits | Status |
|---|---|---|---|---|---|---|
| 6CH-940 (Front access skim filter) | 6CH-940 | PWW50P3 | FC-0359 | 6" (152 mm) × 8-1/4" (210 mm), 45 sq ft | not listed | verified |
| 6CH-941 (Front access, stacked upper) | 6CH-941 | not listed | FC-0360 | 6" (152 mm) × 8-1/4" (210 mm), 45 sq ft | not listed | verified |
| 6CH-942 (Front access, stacked lower) | 6CH-942 | not listed | FC-0361 | 6" (152 mm) × 8-1/4" (210 mm), 45 sq ft | not listed | verified |
| 4CH-926 (Teleweir) | 4CH-926 | PWW25L | FC-0168 | 4-15/16" (125 mm) × 13-1/2" (343 mm), 25 sq ft | not listed | verified |
| 4CH-935 (Teleweir) | 4CH-935 | PWW35L | FC-0170 | 4-15/16" (125 mm) × 9-1/4" (235 mm), 35 sq ft | not listed | verified |
| 4CH-949 (Teleweir) | 4CH-949 | PWW50L | FC-0172 | 4-15/16" (125 mm) × 13-1/2" (343 mm), 50 sq ft | not listed | verified |
| C-4310 (Skim filter 10) | C-4310 | PWW10 | FC-3077 | 4-1/4" (108 mm) × 4" (102 mm), 10 sq ft | not listed | verified |
| C-4326 (Top load 25) | C-4326 | PRB25-IN | FC-2375 | 4-15/16" (125 mm) × 13-5/16" (338 mm), 25 sq ft | not listed | verified |
| C-4950 (Top load 50) | C-4950 | PRB50-IN | FC-2390 | 4-15/16" (125 mm) × 13-5/16" (338 mm), 50 sq ft | not listed | verified |
| C-4970 (Top load 75, discontinued by Unicel) | C-4970 | not listed | FC-2930 | 4-15/16" (125 mm) × 23-5/8" (600 mm), 75 sq ft | not listed | verified |
| C-4995 (Top load, the C-4970 replacement) | C-4995 | PCAL100 | FC-2940 | 4-15/16" (125 mm) × 23-5/8" (600 mm), 95 sq ft | not listed | verified |
| C-6375 (Dyna-Flo XL) | C-6375 | not listed | FC-3754 | 6-9/16" (167 mm) × 13-5/16" (338 mm), 75 sq ft | not listed | verified |
Know your model but not the part number? See Waterway Plastics filter by model and year.
Brands that share cartridges with Waterway Plastics
- Master Spas, same part numbers 6CH-940, 4CH-935, 4CH-949
- PDC Spas, same part numbers 4CH-949, C-4310, C-4326
- Beachcomber, same part numbers C-4326, C-4950
- Bullfrog, same part numbers 6CH-940, C-4950
- Cal Spas, same part numbers C-4950, C-4995
Guides that apply to Waterway Plastics
- Housings that hold more than one cartridge
- Why 817-4025 and 817-4050 share a length
- 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 Waterway Plastics 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
-
6CH-940 cartridge (OEM 817-0050) -
6CH-941 cartridge (OEM 817-0011) 6" × 8-1/4"
-
6CH-942 cartridge (OEM 817-0012) 6" × 8-1/4"
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4CH-926 cartridge (OEM 817-4025) 4-15/16" × 13-1/2"
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.