i've found some anwers from the ge web site:
it seems RO systems filter out minerals that regular filters don't
catch. among them:
what does this stuff do to the water? to plants? to people?
also, there are two types of 2stage filters by ge:
volitile organic compound
and the other reduces:
what are the differences between these items. should i use both
the common stuff that all these filters take out are lead,mercury,
atrazine, lindane, cysts, asbestos, turbidity, the taste and odor of
clorine, sedimenta and rust.
and, anybody know why water is wasted with RO?