We no longer offer our how-to build your own survivalist water filter DVD as a free gift or for sale. Never drink water from a stream, creek, river, lake or pond unless you are in a life or death situation. To purify water boil for 5 minutes, or use bleach or hydrogen peroxide or iodine. You must have healthy water to survive. When hiking, exploring or in a survival situation, make sure you have access to healthy water.