DIY Water Filter. Homemade “High-Volume” Water Filter. Easy DIY. Fast Filtering – makes a glassful in seconds (whole gallon in just over 3 minutes). low cost ~ only .00 for supplies ( for the carbon and for the coffee filters). with proper maintenance it should last for years. removes virtually all sediment, any bad odors/smells/tastes and over 200 chemical contaminants (including herbicides, pesticides, pharmaceuticals etc.). i constructed it mainly to make my tap water taste good (it’s so full of chlorine and other junk, i can barely keep it down). use the filtered water for drinking, cooking, making ice etc. works perfect with any tap water (rain water too). can also be used with pond/river water (just boil it first, to remove any pathogens) then put it thru the filter. tips: construct using a one liter bottle and the whole carton of carbon for maximum filtering. double up the screen inside the bottle cap if necessary. use a new coffee filter between uses. when done using it, discard the coffee filter and remove diffuser to dry.