neuronboy No that won't do. That is how you make lye by running water through wood ashes. Now I don't know about you but I treally wouldn't want to drink lye even if it is greatly deluted.

A sand filter is suppose to be a way to remove most solids from water. And charcoal does remove most chemical compounds. So you can make a several layered filter combining both. I would still boil or better yet distill the result just to be safe.

The best charcoal to use is activated charcoal. The difference is the charcoal is heated to high temps. under pressure with steam. Something like 900 degrees. Much beyond the capacity of most. What this does is somehow opens up the charcoal to expose much more surface area. The surface is what captures the contaminants.

Using regular charcoal would require much more that activated. So it would need to be changed out more frequently.