💧 Darlly Filtration 42513 Replacement Filter Cartridge — 25 sq ft
This is a 25 sq ft replacement filter cartridge from Darlly Filtration, part number 42513. It measures 4-15/16″ in diameter and 13-5/16″ long, with a 2-1/8″ open top and a 2-1/8″ open bottom. It uses 3 oz filter media. It is listed for the equipment shown below, so check the model on your own unit against that list. If your old part carries one of the cross-reference numbers further down, this is listed as its alternative.
📏 Specifications
| Specification | Value |
|---|---|
| Brand | Darlly Filtration |
| Manufacturer part number | 42513 |
| Bottom Physical Dimension | 2-1/8″ |
| Bottom Style | Open |
| Diameter | 4-15/16″ |
| Length | 13-5/16″ |
| Media Type | 3 oz |
| Square Footage | 25 sq ft |
| Top Physical Dimension | 2-1/8″ |
| Top Style | Open |
| Catalog description | Crtrdg, 25sqft,2-1/8″ot,2-1/8″ob, 4-15/16″dia,13-5/16″L, 3oz |
✅ Listed for
- In-Line
- Skim Filter 25sqft (3oz)
- Mytilus MY 30/50
- Rainbow Dynamic 25sqft (3oz)
- Ultra Skim Filter 25sqft
- Pentair Rainbow RDC Series Inline Filter
- Pentair Rainbow RTL/RCF Series Top Load Inline Filter
- Waterway In-Line Filter
- Waterway Top Load Filter
- Waterway Top Mount Skim Filter
- Pentair Rainbow Dynamic Series IV Skim Filter
- Waterway Flo-Pro Above Ground Skim Filter
🛁 Spa makes it is listed for
Accent Spas, Acryx-Maax (Canada), Apollo Spas, Aqua Mystic, Arctic Spas, Beachcomber, Blue Falls (Canada), Coast Mountain Spas (Canada), Coleman Spas (Maax), Custom Molded Products, Dakota Spas, Diamond Spas, Emerald Spas, GPM Industries, Great Lakes Spas, Great Northern Engineering, Honey Tubs, Hot Spot (Watkins), Infinity Spas, Leisure Bay/Rec Whs, Lifestyle Spas (Canada), Maax Spas, Maax Spas/Coleman, Moonwater Spas, Nordic Hot Tubs, Orca Bay Spas, PacFab/Pentair, QCA, Rainbow/Pentair, Rec Whs/Leisure Bay, River Valley Spas, Rubadub Tub, Safari Spas, Signature Spas, Spa Manufacturers, Inc., Streamline Spas, Sun Ray Spas, Thermo Spas, US Spas, Viking Spas, Waterway, Watkins Mfg/Hot Spot.
🔄 Cross-reference part numbers
These part numbers are listed as alternatives for this part.
| Brand | Part number |
|---|---|
| Filbur | FC-2375 |
| Filbur | FC-2375M |
| Filbur | PC-2375 |
| Pleatco | PRB25-IN |
📐 How to check the size
Measure your old cartridge from end to end for the length, and across the pleats at the widest point for the diameter. Then check the hole in the center of each end cap: an open end has a hole straight through, a closed end is solid. All of these should match the specifications table above.



