Description
The Magnum P100 filter cartridge is made in New Zealand as a direct fit for Poolquip and Paramount Pools P4 housings, and some Filtermaster housings. It’s built to the exact dimensions the P4 housing needs, so there’s no guesswork on fit.
Dimensions
| Measurement | Size |
|---|---|
| Outside diameter (width) | 185mm |
| Outside length | 493mm |
| Internal diameter (hole) | 75mm |
Why You Need It
A pool or spa filter cartridge loses efficiency as it collects debris and fine particulates, and a cartridge that doesn’t match your housing’s exact dimensions can leave gaps that let unfiltered water bypass the media entirely. Replacing your P4 housing cartridge with the correctly sized Magnum P100 keeps water clarity and filtration performance where they should be.
FAQs
How do I know if my housing is a genuine Poolquip P4?
Check the housing markings or measure the cartridge cavity. If it matches 185mm outside diameter, 493mm length, and a 75mm centre hole, the P100 will fit. If you’re unsure, the model number is usually printed on the housing lid.
Will this cartridge fit other pool filter brands besides Poolquip and Filtermaster?
It’s designed specifically for Poolquip/Paramount Pools P4 housings and select Filtermaster housings. Fit with other brands isn’t confirmed, so check your housing’s internal dimensions against the specifications above before ordering.
How often should a pool cartridge like this be replaced?
This depends on pool usage, bather load, and how often the cartridge is cleaned versus replaced outright. As a general guide, most pool cartridges need replacing every 12-24 months, sooner with heavy use.
Can I clean the cartridge instead of replacing it on schedule?
Cleaning removes surface debris but doesn’t restore the media itself. Pleated and depth cartridges gradually lose their ability to release trapped particles, even after a good rinse. Flow drops and filtration weakens over repeated cycles, so replacement on schedule is what actually keeps performance steady, not cleaning alone.
What happens if I use a cartridge that’s slightly the wrong size?
Water finds the path of least resistance. An undersized cartridge leaves a gap against the housing wall, and water pushes through that gap instead of the filter media. Debris and contaminants ride straight through with it. This isn’t a cosmetic mismatch; it’s a functional failure of the filter.
Do I have to commit to a subscription, or can I order once?
Either works. A one-off order suits most people. If you’d rather not think about timing, the recurring purchase option handles scheduled replacements automatically.