Darlly 70521 Spa Filter Cartridge
Replaces Unicel 7CH-552
- Diameter × length
- 7" × 10-1/2"
- Filter area
- 52 sq ft
- End caps
- semi-circular Handle / 2" male thread/MPT
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 70521 is a 52 sq ft spa filter cartridge, 7" x 10-1/2". It replaces Unicel 7CH-552.
Specifications
| Darlly part number | 70521 |
|---|---|
| Outside diameter | 7" |
| Length | 10-1/2" |
| Top end cap | semi-circular Handle |
| Bottom end cap | 2" male thread/MPT |
| Filter area | 52 sq ft |
| Type | Spa |
| Darlly description | top load-Dimension One Spas |
Cross-reference
| Brand | Part numbers Darlly 70521 replaces |
|---|---|
| Unicel | 7CH-552 |
Older or other numbers that also point to this cartridge (not confirmed by a second source): PTL55XW-F2M (Pleatco), FC-0465 (Filbur).
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 7CH-552?
- Darlly 70521 replaces Unicel 7CH-552. Both are 7" in diameter and about 10-1/2" long.
- What size is Darlly 70521?
- Darlly 70521 is 7" in outside diameter and 10-1/2" 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.