Darlly 80521 Pool Filter Cartridge
Replaces Unicel SC3-SR50
- Diameter × length
- 8-11/16" × 13-5/16"
- Filter area
- 52 sq ft
- End caps
- 4-3/16" Open / 4-3/16" Open w/ 12 concentric slots
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 80521 is a 52 sq ft pool filter cartridge, 8-11/16" x 13-5/16". It replaces Unicel SC3-SR50.
Specifications
| Darlly part number | 80521 |
|---|---|
| Outside diameter | 8-11/16" |
| Length | 13-5/16" |
| Top end cap | 4-3/16" Open |
| Bottom end cap | 4-3/16" Open w/ 12 concentric slots |
| Filter area | 52 sq ft |
| Type | Pool |
| Darlly description | Sta-Rite 50TX, 50GPM-TX, 50TXR, T-50TX, T-50TXR, PTM50 |
Cross-reference
| Brand | Part numbers Darlly 80521 replaces |
|---|---|
| Unicel | SC3-SR50 |
Other Darlly cartridges the same size
Same diameter and length. Check the end caps and area before swapping.
Questions
- What is the Darlly replacement for Unicel SC3-SR50?
- Darlly 80521 replaces Unicel SC3-SR50. Both are 8-11/16" in diameter and about 13-5/16" long.
- What size is Darlly 80521?
- Darlly 80521 is 8-11/16" in outside diameter and 13-5/16" long, with 52 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.