Darlly 51002 Spa Filter Cartridge
Replaces Unicel C-5396 · Pleatco PCST80 · Filbur FC-2975
- Diameter × length
- 5-5/16" × 21-5/16"
- Filter area
- 100 sq ft
- End caps
- 2-1/8" Open / 2-1/8" Open
Pool and spa businesses in Florida, Georgia, South Carolina, Alabama, Mississippi, Louisiana and Texas order through their Grit Game rep. Everywhere else, contact Darlly Filtration directly.
Darlly 51002 is a 100 sq ft spa filter cartridge, 5-5/16" x 21-5/16". It replaces Unicel C-5396, Pleatco PCST80 and Filbur FC-2975.
Specifications
| Darlly part number | 51002 |
|---|---|
| Outside diameter | 5-5/16" |
| Length | 21-5/16" |
| Top end cap | 2-1/8" Open |
| Bottom end cap | 2-1/8" Open |
| Filter area | 100 sq ft |
| Type | Spa |
| Darlly description | Waterway, Coast Spas |
Cross-reference
| Brand | Part numbers Darlly 51002 replaces |
|---|---|
| Unicel | C-5396 |
| Pleatco | PCST80 |
| Filbur | FC-2975 |
Older or other numbers that also point to this cartridge (not confirmed by a second source): PLST80 (Pleatco).
Questions
- What is the Darlly replacement for Unicel C-5396?
- Darlly 51002 replaces Unicel C-5396. Both are 5-5/16" in diameter and about 21-5/16" long.
- What Darlly cartridge replaces Pleatco PCST80?
- Darlly 51002 replaces Pleatco PCST80.
- What size is Darlly 51002?
- Darlly 51002 is 5-5/16" in outside diameter and 21-5/16" long, with 100 sq ft of filter area.
Cross-reference checked October 21, 2026 against Unicel's 2026 Replacement Guide, Pleatco's catalog (updated September 2025), filbur.com and darllyfilter.com. A competitor number is listed only when that brand's own data pairs it with the same cartridge size. Always compare the size and end caps of your old cartridge before ordering.
Brand names and part numbers are trademarks of their respective owners and are shown only to identify compatible replacements. Darlly Filtration is not affiliated with or endorsed by them. Cross-reference by The Grit Game, Darlly's sales agency.