a,

I have read about using sand to clean water and it looked to me to be very viable. I was researching ways to clean up 'gray water' and the water from roof collection to use in the garden and possibly get the water to the point of drinking. Cleaner than municiple water *for sure*!!! I know someone north of me who tested his rain colletion water against the city and the stuff off the roof was cleaner for drinking!!

Been doing some more reading and thinking about terra preta, will post it here when I finish.