Name: Unicel UHD-SR50 Replacement Filter Cartridge 52 sq. ft. | Sta-Rite Posi-Flo 50
Brand: Unicel
SKU: UHD-SR50
Price: 65.99 USD
Availability: InStock

Cylindrical pleated white pool filter cartridge with blue top and orange bottom edges and product label on front

Cylindrical pool filter cartridge with white pleated material, blue top, and red bottom against a white background

Cylindrical pool filter cartridge with blue plastic top and white pleated filter material inside

cylindrical replacement filter cartridge with pleated white filtering material and bright orange plastic end cap

$65.99

$9.99 flat shipping on orders under $100.

Unicel Authorized Dealer Full Manufacturer Warranty Support

No Hassle Returns 30 Days Paid Returns

In stock, ready to ship
Backordered: contact us for ETA

SKU:: UHD-SR50

Poolaroo Promise
- Fast Shipping — Ships in 1–2 Business Days
- 30-Day Risk-Free Returns — We Pay Return Shipping, No Restocking Fees
- Powered By People Who Care - No Faceless Conglomerate

About This Item

The Unicel UHD-SR50 is a premium UHD Series replacement filter cartridge delivering 52 sq. ft. of heavy-duty filtration area for Sta-Rite Posi-Flo 50 pool and spa filter systems. Built with 4 oz. Reemay 2040 heavy-duty polyester filtration media — a full ounce heavier than standard 3 oz. cartridges — the UHD-SR50 delivers superior dirt-holding capacity, enhanced durability, and extended service intervals. With 195 precision-formed pleats maximizing media surface contact and a reinforced polypropylene core, this is the OEM-grade replacement your Posi-Flo 50 deserves.

Specifications

Filter Area	52 sq. ft.
Length	13 5/16"
Outer Diameter	8 11/16"
Top Inner Diameter	4 3/16"
Bottom Inner Diameter	4 3/16"
Material	4 oz. Reemay 2040
Pleat Count	195
Top Cap: open	Bottom Cap: open w/ 12 concentric slots

Note from Unicel: Replacement cartridge features a blue top end cap and orange bottom end cap.

Fits Into:

OEM Brand	Product Name	Part Number	Notes
Sta-Rite	Posi-Flo 50GPM-TX	WC108-56S2X / 177007	WC108-56S2X = legacy Sta-Rite part; 177007 = current Pentair part
Sta-Rite	Posi-Flo 50TX	WC108-56S2X / 177007	WC108-56S2X = legacy Sta-Rite part; 177007 = current Pentair part
Sta-Rite	Posi-Flo 50TXR	WC108-56S2X / 177007	WC108-56S2X = legacy Sta-Rite part; 177007 = current Pentair part
Sta-Rite	Posi-Flo T-50TX	WC108-56S2X / 177007	WC108-56S2X = legacy Sta-Rite part; 177007 = current Pentair part
Sta-Rite	Posi-Flo T-50TXR	WC108-56S2X / 177007	WC108-56S2X = legacy Sta-Rite part; 177007 = current Pentair part
Sta-Rite	Posi-Flo II PTM50	WC108-56S2X / 177007	WC108-56S2X = legacy Sta-Rite part; 177007 = current Pentair part

(This is not an exhaustive list.)

Also known as: UHDSR50

About Unicel Filter Cartridges and DE Grids

The "Gold Standard" of Replacement Cartridges
For over 50 years, Unicel (Meissner Mfg.) has been the professional's choice for restoring pool water clarity. While generic "knock-off" filters often use cheap, fuzzy fabric that clogs quickly, Unicel uses genuine Reemay® Filtration Media. This patented synthetic fiber features a unique trilobal shape that traps significantly more dirt and oils without choking your pump's water flow. Based in California, Unicel doesn't just copy filter dimensions; they engineer them to strict Original Equipment Manufacturer (OEM) specifications. This ensures a "lock-tight" fit in your filter tank, preventing debris from bypassing the system and returning to your pool.

Why We Trust Unicel Filter Cartridges and DE Grids: Genuine Reemay® Media: Uses continuous trilobal fibers to capture microscopic debris without restricting water flow.

Precision "Exact Fit": Engineered to match your tank's original specifications for a 100% leak-free seal.

Made in the USA: Manufactured in California with heavy-duty urethane end caps that resist cracking under pressure.

Longer Lifespan: Sharp, rigid pleats resist collapsing during cleaning, meaning you buy fewer replacements over time.

Visit Manufacturer Site →