The Neto Water Filter Bag uses wood discs to filter out contaminants, bacteria, and viruses from dirty water to provide portable drinking water for backpacking and off-the-grid living. It is powered by gravity. It uses the xylem tissue in sapwood as a filter, which is between 10 and 100 times cheaper than ultrafilters (hollow membrane filters). To make the filters, a tree branch is sliced into cross-sectional discs, which then undergo a natural chemical process to allow them to last two years in storage. The resulting innovation overcomes several environmental issues while using a natural and renewable resources.