What is the Darlly replacement for Unicel C-8413?

Darlly 81253 replaces Unicel C-8413. Both are 8-15/16" in diameter and about 28-3/16" long.

What Darlly cartridge replaces Pleatco ULTRA-B5?

Darlly 81253 replaces Pleatco ULTRA-B5.

What size is Darlly 81253?

Darlly 81253 is 8-15/16" in outside diameter and 28-3/16" long, with 125 sq ft of filter area.

Darlly 81253 Pool Filter Cartridge

Replaces Unicel C-8413 · Pleatco ULTRA-B5 · Filbur FC-2575

Darlly 81253 is a 125 sq ft pool filter cartridge, 8-15/16" x 28-3/16". It fits the Sta-Rite Posi-Clear PXC-125 and Waterway Pro-Clean 125 with the 28-3/16" cartridge (817-0125P). It replaces Unicel C-8413, Pleatco ULTRA-B5, Filbur FC-2575, Sta-Rite 25230-0125S and Waterway 817-0125P.

Specifications

Darlly part number	81253
Outside diameter	8-15/16"
Length	28-3/16"
Top end cap	4" Open w/ molded gasket
Bottom end cap	4" Open w/ molded gasket
Filter area	125 sq ft
Type	Pool
Darlly description	Sta-Rite PXC-125, Waterway Pro Clean 125

Cross-reference

Brand	Part numbers Darlly 81253 replaces
Unicel	C-8413
Pleatco	ULTRA-B5
Filbur	FC-2575
Hurricane (former brand)	HF8413-01
OEM and other numbers	Sta-Rite 25230-0125S, Waterway 817-0125P

Filters it fits

Filter	Cartridges per filter	OEM cartridge number
Sta-Rite Posi-Clear PXC-125; Waterway Pro-Clean 125 with the 28-3/16" cartridge (817-0125P) (125 sq ft filter)	1	25230-0125S, 817-0125P

81253 (125 sq ft) and 81504 (150 sq ft) both fit the Posi-Clear PXC-125.

Other Darlly cartridges the same size

Same diameter and length. Check the end caps and area before swapping.

Darlly 81504150 sq ft · Sta-Rite Posi-Clear PXC-125 (150 sq ft element)…Darlly 81756175 sq ft · Hayward Star-Clear Plus C1750 Darlly 82002200 sq ft · Hayward Star-Clear Plus C1900

Questions

What is the Darlly replacement for Unicel C-8413?: Darlly 81253 replaces Unicel C-8413. Both are 8-15/16" in diameter and about 28-3/16" long.
What Darlly cartridge replaces Pleatco ULTRA-B5?: Darlly 81253 replaces Pleatco ULTRA-B5.
What size is Darlly 81253?: Darlly 81253 is 8-15/16" in outside diameter and 28-3/16" long, with 125 sq ft of filter area.

Where to buy Darlly 81253

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.

Find your Grit Game rep Contact Darlly Darlly 81253 on darllyfilter.com

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.