Cartridge record

Unicel C-6601

Name: Unicel C-6601 filter cartridge
Brand: Unicel
SKU: C-6601

Also sold asPleatco PAQ25-OFilbur FC-3083

cross-checked against 2 sourcesDiscontinuedReplacement: 6CH-35

Verified specifications

The selected value is shown first. Expand any row to compare the source values retained by the dataset.

Cartridge specifications
Outside diameter	6" Source values unicel 6" pleatco 6"
Length	9-3/4" Source values unicel 9-3/4" pleatco 9-7/8"
Top cap	/ semi-circular handle Source values unicel / semi-circular handle pleatco Handle
Bottom cap	1-7/8" / open w/ slots Source values unicel 1-7/8" / open w/ slots pleatco 1 15/16
Pleats	111 Source values unicel 111
Filter area	25 sq ft Source values unicel 25 pleatco 25
Media weight	4 oz Source values unicel 4 pleatco 4

Match the complete printed string. Similar-looking part numbers can describe different end caps or lengths.

Cross-reference equivalents
Brand	Part number	Verification
Unicel	C-6601	cross-checked against 2 sources
Pleatco	PAQ25-O	single-source
Filbur	FC-3083	single-source

Fitments are source-attributed. Confirm the housing model and cartridge measurements before ordering.

Filter and spa fitments
Brand	Model	OEM part	Source
Aqua Spa	—	—	unicel single-source
Aqua Spas	Four Seasons/Aqua Spa 25	—	pleatco single-source
Four Seasons Spas	Four Seasons/Aqua Spa 25	—	pleatco single-source
Four Seasons	—	—	unicel single-source

“The C-6601 has been discontinued by Unicel. Use 6CH-35 (35 sq.ft.) or 6CH-47 (47 sq.ft.) if PAD adapter is MPT, or 6CH-940 if”
Source: unicel
“The C-6601 has been discontinued by Unicel. Use 6CH-35 (35 sq.ft.) or 6CH-47 (47 sq.ft.) if PAD adapter is MPT, or 6CH-940 if PAD”
Source: unicel

Records with the same outside diameter and a different length appear first, followed by the closest diameters. End-cap details still need to match.

6" × 9-7/8"

6" × 9-1/2"

6" × 9-1/8"

6" × 10-1/2"

6" × 10-1/2"

Outbound retailer searches are provided for convenience; Pool Filter Lab is not the seller.