You can't count on expensive filters and power hungry distillers when SHTF. What will you do when tap water is declared unsafe to drink and bottled water runs out? Our biggest threat in this age is microcystins. To find out more about these deadly toxins, how they can and have shut down the tap and how to filter them out while everyone else is getting sick; see this post. Not to be dramatic but the lives of your family may depend on it. All you need is a vessel, dirt, wood, fire, and of course; water. If you have those ingredients you are set for life.