Check this info from the Centers for Disease Control: Drinking Water Treatment Methods for Backcountry and Travel Use and accompanying text.

Note also that the label on Aquamira liquid says it kills bacteria and viruses. The big problem is actual protozoa (giardia and cryptosporidium) which are a lot harder to kill with chemicals.

Note also the recommended filter size in the CDC literature, which rules out the Aquamira Frontier Pro filter (3.0 microns) for filtering protozoa. I had to spend almost a half hour to get the Frontier Pro's micron size information, which was not on the Aquamira website or on the packaging, but was in an obscure place on the McNett website (parent company). IMHO, it is extremely dishonest of this company not to disclose the filter size openly! For that reason alone, I do not trust their products!