@sueinmn I have a question. First, that is very good info. Many years ago half the members of my family contracted giardiasis when we lived in Berlin, New Hampshire. It was not able to be filtered out of the town water supply because of its size. It had apparently gotten into the water when a military group had been up there doing exercises or something we were told. We were also told something about beavers connected to that. Who knows. Anyway, if filters are made to get rid of it, wouldn’t all municipal water systems have such a filter now since giardiasis is a third world country thing? Thank you. (Irene5)