Description
xAQUALTRA's PRB35-IN replacement spa filter cartridge is a NSF-certified, washable 5" x 9 1/4" drop-in filter designed to fit popular 35 sq. ft. hot tub filter housings and restore clear, comfortable water.
This two-pack of AQUALTRA spa filters is built to match the dimensions and openings of common PRB35-IN-style cartridges, delivering a direct replacement option that combines durable construction with effective mechanical filtration. The cartridges use a PET composite media and chlorine-resistant end caps to stand up to regular hot tub sanitizers while remaining BPA-free and NSF/ANSI certified for material safety.
Will this filter physically fit my hot tub?
Measure your existing cartridge to confirm compatibility: these AQUALTRA filters are 5 inches outer diameter and 9 1/4 inches long, with 2 1/8 inch top and bottom openings. They match many part numbers used by major manufacturers and are intended as drop-in replacements when the dimensions align.
- Outer diameter: 5" (127 mm)
- Length: 9 1/4" (235 mm)
- Top & bottom opening: 2 1/8" (54 mm)
- Filtration area: 35 sq. ft.
How well does it remove debris from spa water?
AQUALTRA cartridges use a PET composite element and a "dirt-locking" fabric structure that traps hair, leaves, sediment, and fine particles more effectively than ordinary pleated media. The construction helps keep floating and suspended contaminants out of circulation, improving clarity between deep cleans.
- Effective against hair, dust, sand, and leaves
- 35 sq. ft. media surface for increased dirt-holding
- Reduces frequency of heavy maintenance when used with routine cleaning
Can I clean and reuse these cartridges?
Yes — the AQUALTRA PRB35-IN filters are designed to be rinsed and reused, which lowers replacement frequency and reduces waste. For best results, rinse every two weeks and remove the filter before soaking in any chemical cleaners to avoid corrosion of metal parts.
- Washable PET composite fabric for repeated use
- Recommended rinse interval: about every 2 weeks
- Remove filter from hot tub before backwashing or soaking
Are these filters safe with hot tub chemicals?
The cartridge components — PET composite media, high-chlorine-resistant end caps, and polypropylene core — are selected to tolerate typical spa sanitizers and water care routines. The materials are BPA-free and tested against NSF/ANSI standards for material safety; however, always follow your sanitizer manufacturer's guidance for chemical concentrations and exposure times.
- BPA-free materials and NSF/ANSI certified components
- Chlorine-resistant end caps to extend service life
- Follow chemical manufacturer recommendations to prolong filter life
Who is this for? This AQUALTRA two-pack is aimed at hot tub and spa owners who need a direct, reliable replacement for 35 sq. ft. drop-in cartridges — especially those with PRB35-IN-style housings or matching part numbers such as C-4335, FC-2385, Waterway 35, and Guardian 409-219. Choose this set if you want NSF-certified materials, washable media to cut down on replacements, and a close dimensional match for common aftermarket filter bays. Before purchasing, confirm your existing cartridge dimensions and compatibility to ensure a correct fit.
FAQ
Q: Which hot tub models is this filter compatible with?
A: It fits PRB35-IN style housings and many parts like C-4335, FC-2385, Waterway 35, and Guardian 409-219 when dimensions match.
Q: How often should I clean these filters?
A: Rinse the filter roughly every two weeks; more often with heavy use or visible debris.
Delivery & Returns
xFree UK delivery on every order — packed within 1 business day, arriving in 2–4 business days.
Free 30-day returns — email us for a prepaid label; refunds land within 3–5 business days of the return arriving.
Why GardenLuxe
x- ✓ Proven best-sellers only — products UK gardens buy again and again
- ✓ Free UK delivery on every order
- ✓ Free 30-day returns with prepaid label
- ✓ Genuine products from reputable suppliers
- ✓ Human support — gardenluxe.co.uk@gmail.com
Care & Good To Know
x- Rugs & mats: hose down or machine wash per label; air-dry fully before storing.
- Shade cloth: use every grommet, tension with bungee ties, take down for winter storms.
- Fertilisers & plant food: always follow label dose rates; store sealed, dry and away from children and pets.
- Power tool parts: check bar length and pitch/gauge match your saw before fitting.
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