Im sure you guys all know but i didnt see it any where so I posted it. A good rule for boiling water to purify it is to remember this "Big bubbles no troubles" the bigger the bubbles are the safer it is to drink. Once you have a good rolling boil it should be safe to drink. Before you boil water try to get stuff out like bugs and leaves. To do that use a Tshirt and pour water through it. I have a millbank bag thats designed to remove big stuff like bugs and leaves etc.