Free Clean Water-Cisterns

     Cisterns are an ancient means of collecting and storing rainwater.  Cisterns have literally been used by all ancient peoples to collect and store rain water  For more information on the history of cisterns go to: .http://en.wikipedia.org/wiki/Cistern
     It is possible, in most areas, to collect enough water for your home without being on the grid and purchasing from the county or city.  The method is simple; you dig enough space for two identical water proof tanks in the ground.  12 feet by 8 feet by 8 feet is the smallest I have heard of.  The 8 feet by 8 feet seems standard today with length being 15 feet, 20 feet all depending on the space you have available.  Or you may want to work above ground.  Here is a youtube video of an above ground collection tank:  http://www.youtube.com/watch?v=besl1h6t6FA  .  Her also are plans for an above ground system:  http://www.watersanitationhygiene.org/References/EH_KEY_REFERENCES/WATER/Reservoirs/Constructing%20a%20Household%20Cistern%20%28USAID%29.pdf
     You want two identical tanks because clean water grows algae and the water must be flushed into another tank to facilitate cleaning.  Proper method to clean a tank are:  http://www.scphoh.org/environmental/ENV_PDFs/WAterPDFs/ProceduresforCleaningCisterns.pdf
     Most tanks are constructed of concrete or cinder block.  It is best to line this tank with glass to maintain the purity of the water otherwise it will need to be filtered before use in the house.  If it is glass lined you need only run all the rain water from your gutters through a large pickle barrel that has three sections inside; top layer is sand, middle layer is charcoal, bottom layer is sand; all in equal proportions.
     If you prefer other methods of filtering there are several places to check:  http://www.motherearthnews.com/sustainable-farming/old-farm-magazines-zmaz72ndzhar.aspx and http://www.waterfiltrationcompany.com/cisternfilter.htm If these weren't what you had in mind here is another type of filter: http://www.freedrinkingwater.com/water-education2/9-cistern-water.htm    

Note:  All cisterns have soft water.  There will be no trace elements as it is collected rain water.