Having a method of purifying water is one of the most important parts of disaster prepping. But it is also one of the most confusing. There is a LOT of information out there about water purification systems, and a lot of the info is purposely misleading because companies want you to buy their products. The reality is that There is no one “best” method of purifying water in disaster situations. Which water purification method to use depends on your situation and the types of threats present.