What is the minimum filter size needed to effectively filter out Giardia?

The minimum filter size needed to effectively filter out Giardia is one micron. Giardia is a genus of protozoan parasites that can be found in contaminated water sources. The cysts of Giardia are typically around 10 to 14 microns in size, so to ensure effective removal, a filter size of one micron or smaller is recommended. This size allows for the trapping of the cysts, thus preventing them from passing through the filter into the treated water. Filters rated for one micron can handle diverse particle sizes including bacteria and protozoan cysts, making them suitable for providing safe drinking water.

While options such as five, six, and ten microns may seem close, they would not adequately remove Giardia cysts, as the cysts would likely pass through filters of these larger sizes. This underscores the importance of selecting a filtration system with an appropriate pore size that ensures the removal of waterborne pathogens like Giardia.