What is the pore size of the hollow fiber microfilter? 10 July 2023 11:28 Updated The Pore Size of the Hollow Fibre Membrane is 0.2 microns. Related articles Can I drink pool water or salt water with the camelbak filtered by LifeStraw® filter? How often do I need to replace my whole filter set? How do I remove the activated carbon filter from my LifeStraw® reservoir filter? What replacement filters fit which size bottle? how can I see what size I have now?