What hot tub filter cartridges should I look for?

[Dom9]

I want spare filters before summer use gets heavy. How do I avoid buying the wrong ones?

[Gareth19]

Match the filter type to your hot tub model. For Intex PureSpa models that use S1 filters, Intex 29001E PureSpa Type S1 Filter Cartridge 2 Pack is a verified option

[Compass]

If you want a larger pack, Intex PureSpa Type S1 Easy Set Pool Filter Replacement Cartridges Filters is another real S1 filter listing

[Tel92]

Do not buy purely on looks, because cartridge dimensions and type matter

[TheLegendBrett88]

I would rather keep spare filters ready than discover they are clogged when the tub is already filled