Description
Meet the Darlly Spa/Pool Replacement Filter Cartridge [81003] (UHD-SR100) — a purpose-built cartridge designed to keep spa and pool water sparkling clean with dependable, easy filtration. Engineered to slot into StaRite/Pentair systems and to replace a broad range of older filter cores, this cartridge delivers consistent performance season after season.
Overview
- Media: 4 oz filtration media for solid debris and fine particulates
- Filtration area: 102 square feet of surface media coverage for efficient flow and dirt holding capacity
- Top style: Open
- Bottom style: Open with Slots for enhanced debris capture
- Physical dimensions: Diameter 8-11/16", Length 25-11/16"
- Top footprint: 4-3/16"
- Application: Compatible with StaRite/Pentair pools and spas, model family including UHD-SR100
- Replaces: 177009, 20201ECO, 46171, 645544025500, AK-8020, FC-2550, PLE-051-9183, PLE-051-9601, PSR100, PSR100-4, UHD-SR100, WC108-58S2X
- Model lineage: Posi-Flo TX/TXR/PTM 100 family compatibility
Why this cartridge stands out
What sets the 81003 cartridge apart is its combination of robust filtration media and a design optimized for heavy-use spa and pool systems. The open-top design simplifies installation and inspection, while the open-with-slots bottom maximizes debris capture near the intake, helping prevent clogging and maintaining steady circulation. The 102 sq ft media area delivers a higher dirt-holding capacity than many standard cartridges, translating to longer intervals between cleanings and clearer water.
Ideal use cases
- Residential hot tubs and spas that require reliable, consistent filtration with minimal disruption.
- In-ground and above-ground pool systems using StaRite/Pentair filtration cores that need a trusted replacement cartridge with broad compatibility.
- Seasonal pool setups where easy maintenance and long service life are priorities.
Maintenance and care
To maximize life and performance, follow these practical steps:
- Power down the pump before removing or installing cartridges.
- Rinse the cartridge with a garden hose from the interior out to clear loose debris; avoid high-pressure jets that could damage the media.
- Inspect for cracks or deformation—replace if the cartridge shows wear.
- Periodically deep-clean with a cartridge cleaner according to the cleaner’s instructions, then rinse thoroughly and let air-dry before reinstalling.
- Frequency of cleaning depends on use: more frequent in heavy-use periods or high-contaminant environments.
Installation tips
For a smooth swap to the UHD-SR100 cartridge:
- Power off the filtration system and remove the existing cartridge.
- Check that the replacement’s dimensions align with your housing — diameter, length, and top/bottom configurations match your unit’s specs.
- Insert with the open top facing up and the bottom core seated securely; ensure any end caps or clamps are fastened according to your pump housing design.
- Run the system and check for leaks; recheck the cartridge after initial run time to ensure proper seating.
Upgrade your spa or pool filtration with the Darlly 81003 UHD-SR100 cartridge for reliable performance, broad compatibility, and a filtration solution that helps keep water clear with less maintenance.
| Application | StaRite/Pentair |
| Bottom Physical Dimension | 6" |
| Bottom Style | Open w/Slots |
| Diameter | 8-11/16" |
| Length | 25-11/16" |
| Media Type | 4oz |
| Model | Posi-Flo TX/TXR/PTM 100 |
| Square Footage | 102 sq ft |
| Top Physical Dimension | 4-3/16" |
| Top Style | Open |

