[JD_UTDallas]

There was an article in “National Geographic” a few months back saying you can take ordinary clear plastic water bottles filled with water as clean as you can get and place them in bright sunlight for 6 hours and it will kill all bacteria, virus and parasites. It is best to place them on a reflective surface and don’t bother them until the 6 hours are over.

That method of water sanitation is called the SolDis method the water needs to be in a PET container PVC or polycarbonate containers block the UV light that is doing the killing. Also the water has to be clear if it is turbid the UV cannot penetrate deep enough also not more than 3 inches deep again UV cannot get very deep in water even clear water. 6 hours in full sun 2 DAYS in slightly overcast.

[yarddog]

Thanks for that info. Now that you have pointed it out, I remember it did say PET plastic. How do you tell if it is PET instead of the other types?