Can I use a slow sand filter to purify tap water?
Maybe. It will depend on how much bacteria is in the tap water, and how much chlorine is present in the tap water. If your water comes from a public water supply system, it is unlikely that there will be enough living “good” organisms to start a biological layer in a sand filter ( that is assuming your public water supply is completely filtered and purified ). There must be living microbes in the water to form the biological layer. The physical action of the sand will do some filtering, but a 10 stage carbon filter will be much better at removing harmful chemicals from your tap water. If, however, there are even a small number of living microbes in your tap water, it is likely that a functional bioligical layer will eventually form; but it may take several months for the layer to mature. If you are on a non-public water system ( a private well ) or you get your water from an open stream or irrigation ditch, then a slow sand filter will probably work. back to top 26.