Hi, AlchemySA, Contaminated water is not a suitable medium for the electrolysis of silver into CS/EIS. An EIS generator needs distilled water, which is obviously already decontaminated. The essential issue is availability and cost of distilled water. I pay $1.50 for a gallon of DW at the drugstore. I can make it at home for about $0.35 per gallon, using a $99 electric distiller. That cost could could be reduced by pre-heating in a suitable tea-kettle (e.g. a cast iron japanese tetsubin) over a fire using a free fuel. But if I am going to pre-heat the water, I might as well go the extra step and bring it to a boil, thus sterilizing it.
It is often said that CS can be made for "pennies per gallon." This is misleading. The chief cost of LVDC EIS is in the DW. In the long run, it is less expensive to decontaminate water by other means than to turn it into high quality DW. When ordinary methods of decontamination are lacking (due to disaster or remoteness) a sterilizer/filter like the Katadyn can treat enough water for one or a small number of people for less than the cost of distillation. Water purification by treating it with a CS additive is a different story, however. You can't expect CS to remove or kill the larger parasites, for example, or to desalinate brackish water. The problem of purifying water is vast topic. It usually requires an engineering solution suited to the circumstances. Best regards, Matthew
