I have personally never used a filter and never gotten sick. We have an abundance of streams, creeks and springs so fresh water is always available. The water is filtered through limestone so it's amazingly clear. As for microbes and other micro-nasties, that's never been a problem around here. People make special trips to come and get the water because most of the time it's better than city water. If I absolutely had to though, there is no problem distilling it and taking everything out of it. It's just a big hassle though.