Pure Spa Cartridge Filter - NORTH
Replaces: PWW35L, MA36, 4CH-935
Using super strong endcap material, industry leading Reemay® filtration fabric and efficient free flow cores. Our filters also come in bacteria fighting Microban® material.
Why Reemay?
Excellent uniformity for reliable performance and sparkling water
Higher dirt-holding capacity (less cleaning)
Unique trilobal fibre shape increases filtration performance
Greater strength and stiffness stands up to high pressure and cleaning
What is Microban?
Microban is an antimicrobial product added to Reemay to inhibit the growth of bacteria, mould and mildew.
Microban protection can be found in thousands of consumers, industrial and medical products around the world.
Microban is built into the fabric, so will last the life of the cartridge
Microbes are invisible to the naked eye. They are living cells that can double in number every 20 minutes in hot spa water. They can cause stains and odours and can reduce the life of the filter cartridge.
Pleatco Ref | PWW35L-M |
Unicel Ref | 4CH-935 |
Other Ref | 817-4035 |
Filter Diameter (Range) | 120-129 mm |
Filter Diameter | 127 mm |
Filter Length | 216 mm |
Filter Top | Handle |
Filter Bottom | Female Thread - SAE Course |
Thread OD | 48 mm |
Filtration Area | 35 sq.ft |
Suitable For | Waterway Plastics |
Maintaining Your Filter Cartridge
With proper care, a filter cartridge can last up to 12 months. Follow these steps:
- Check your spa manual for removal instructions.
- Clean every two weeks using a hose or cartridge cleaning tool.
- Soak in a non-foaming degreaser (e.g., dishwasher detergent or a proprietary cleaner) for at least an hour, preferably overnight. A cleaning powder like Pure-Spa Powder Filter Cleaner is recommended.
- Rinse thoroughly before refitting and allow to dry if possible.
Rotation Method
For optimal performance, we recommend rotating two cartridges: one in use and one on standby. While one is in service, soak the other in detergent for 24–48 hours to remove residues, then let it dry fully before reuse. A dry filter performs better when refitted.
Will a similar-looking filter fit my hot tub?
Sometimes, a filter that’s 5–10mm bigger in height or diameter will still fit, and many people use alternatives if their original is hard to find or discontinued.
Key considerations:
- Top of the filter: If your current filter has a closed top, you can’t use one with an open top, as water will bypass the cartridge.
- Bottom thread: Must match exactly.
- Surface area: If the square footage is within 10–15% of your original and it fits, it’s unlikely to cause issues.
Using a filter too far out of spec can restrict water flow, strain your pump, and potentially damage your hot tub. Always double-check before swapping.