AQUALTRA Hot Tub Spa Filter PRB50-IN Compatible 13 5/16" x 5" Drop-In 2-Pack — Washable, NSF-Compatible

The AQUALTRA PRB50-IN spa filter is a washable, NSF-compatible replacement cartridge sized 13 5/16" x 5" that fits many J-series and Guardian hot tubs and helps trap hair, sand, and debris.

This two-pack of AQUALTRA drop-in hot tub filters is designed for straightforward replacement and regular maintenance. Built with PET composite media, a polypropylene core and chlorine-resistant end caps, the cartridges are BPA-free and made to meet NSF/ANSI material standards. They match the PRB50-IN dimensions and a wide range of OEM part numbers so you can quickly restore circulation and filtration without buying an exact factory-branded cartridge.

Which hot tubs will this filter fit?

The filter matches 13 5/16" length and a 5" outer diameter with a 2 1/8" top and bottom opening, the size specified for PRB50-IN style drop-in cartridges. AQUALTRA lists compatibility with several part numbers used across brands, but confirm physical measurements before ordering.

• Direct dimensions: 13 5/16" long × 5" outer diameter × 2 1/8" openings
• Common compatible references: C-4950, FC-2390, J200–J275 series, Guardian 413-212-02, 373045
• Also fits many third-party part numbers—check your tub’s filter label or measure current cartridge

How does this cartridge improve my spa’s water quality?

AQUALTRA uses a multi-layer PET composite fabric that captures fine particles more effectively than basic pleated paper. The manufacturer describes a "dirt-locking" design that increases contaminant retention so pumps and heaters face fewer clogs, which helps circulation stay efficient between cleanings.

• Fine-particle capture: traps hair, dust, sediment and sand
• Reduces strain on pump by preventing larger debris from recirculating
• Washable fabric extends usable life compared with single-use cartridges

What maintenance does the filter require and how long will it last?

These cartridges are designed to be rinsed and reused, not disposed after one use. Routine cleaning every two weeks is recommended for typical home use; more frequent rinsing is advised for heavy usage or if the tub is outdoors and collects leaves or fine grit.

• Rinse with a garden hose to remove trapped debris; soak in filter cleaner occasionally
• Remove before using strong cleaning chemicals to avoid corrosion of nearby components
• Replace when the pleats show damage or persistent discoloration after cleaning

Are these filters safe and certified?

The components used in this AQUALTRA cartridge are BPA-free and the materials are stated to meet NSF/ANSI material certification standards, indicating suitability for consumer pool and spa environments. AQUALTRA positions this product as an independent aftermarket option rather than an OEM part.

• BPA-free end caps and polypropylene core
• Material certification: conforms to NSF/ANSI criteria for filter materials (as stated by manufacturer)
• Sold as a two-pack so you can keep a spare cartridge on hand

Who this is for: Homeowners and the people who maintain residential hot tubs looking for a cost-effective, reusable replacement cartridge that matches PRB50-IN dimensions. Choose AQUALTRA’s two-pack if you want NSF-compatible materials, easier rinsing between cleanings, and compatibility with many J-series and Guardian-style drop-in filters. Always verify your tub’s filter measurements or OEM part number before purchase to ensure a correct fit.