As we have discussed on this forum before, filtering water for biological is fairly easy with many products available. Chemical pollutants, however, is more difficult. I have found three of products:

Seychelle Water Filters

Renovo Water

H2O Survival Straw

Has anyone had any experience with them? Does anyone have any insight (yes I know there will be many comments)? I am looking for a way of testing them, and if successful, I will post on it.