humm, well i have been trying to NOT get very technical here, in hope those with intrest will do the research, doesnt seem the place to go into a lot of detail so i will keep it simple, anyone seeking clean water, take a look at slow sand filters and activated charcoal, no neither is the perfect answer but i trust inmankind and think most here if they choose learn about water will do the research, i prefeer to keep it simple and not try to scare people with " my knowledge" both slow sand and charcoal activated or not have a use, i did not say to use it, just opened the door to look at a couple of things in use
here is a bit from natures sunshine product

An astonished gathering of the French Academy of Medicine watched as a pharmacist named Touery downed one grain of strychnine (10 times the lethal dose) without any noticeable ill effect! A few years earlier in 1813, another Frenchman swallowed a whole teaspoonful of arsenic trioxide, about 150 times the amount that would have killed most people. He also lived without ill effect. Why? Both of these men had mixed the poison with finely ground charcoal, which has a phenomenal ability to hold poisons from being absorbed by the body. Even so, we do not recommend that you try the above 18th century experiments!
It is important to understand that charcoal (or carbon) does not function like a sponge in pulling into its inner structures various pollutants. Instead, poisonous gases and chemicals adhere or stick to its surface. If you were to eat the carbon, nearby poisons within your body would attach to it firmly until the body expels both of them from the body. The charcoal is not absorbed into the blood, but is merely a carrier of toxins. As far as we know, carbon does not lose any of them prematurely.

What does "Activated" mean? When wood is heated 600 degrees centigrade in a container with the oxygen removed, certain gases and liquids are driven off. It does not 'burn' because the oxygen is missing. (Only a little may be in the wood itself) After this process is completed, steam at 4OO degrees centigrade is introduced (or air is sometimes used), under high pressure. Remember, it is not "absorbed" but 'adheres' to the outer surface of the carbon.

Not only is this state of 'active porosity' obtained by the steam or air pressure process, but simultaneously purifies the product for internal use. Use the powdered form if possible, as commercial tablets are about half as effective and should be chewed.

" after all the debates K.I.S.S. seems to always work best "