Man that show was like 3-4 years ago? I did see they are showing it again. I liked the first season over the second.

I probably would have drank the water the way they did on the show, it was in LA, wasn't it? I think your concerns over what wasn't filtered out is a valid thought that I would have had too but no I do not believe they were given any outside assistance with food and water. That filter was quite large IIRC.