The Berkey water filters are terribly expensive, but very good. Sawyer makes some less expensive ones, they last for an incredibly long time, but they only filter particulates and do not neutralize chemicals. A charcoal filter is typically used to neutralize most chemical impurities. You can actually make your own charcoal filters using, you guessed it...wood charcoal from a wood fire. There are resources online that detail how to make water filters using sand and wood charcoal. These are very effective and useful. A lot of the commercial water filters use coconut hair for their charcoal, but that is not needed for a diy water filter made from a 5 gallon poly bucket from home depot or lowes. Make sure to use the white food grade bucket to eliminate any leaching of polymer chemicals. If you need me to link some articles, I can, but there are a multitude on this topic on the internet.