Malcolm,
'Thank you for your interesting and detailed response.  Would it be alright if 
I forward your post to the people who are asking about RO water?
Nancy...
  ----- 
  Hi;  I wish I knew.  I just finished installing a RO system with a 
de-ionizing (DI) cartridge, so if I want water for drinking or preparing food I 
have the little faucet up on the sink, and if I want DI water, there is a small 
spigot down underneath.  The water from the little faucet tastes better than 
the water straight form the tap - which is pretty good anyway.  The water from 
the DI spigot tastes even better to me, though I have been told that it was 
supposed to taste "flat" because it was without all those wonderful  dissolved 
minerals. Perhaps I have built up a backlog of them or something<g>.  Anyway, I 
normally measure the conductivity of my water before I start a batch of CS - I 
drop the top with it's silver wires down onto the jar, and measure the amount 
of current that passes through the water at the beginning or the process.  
Generally the Distilled water I get around here measures about 0.2 millamps to 
begin, and the CS at the finish seems to be pretty good; clear, slight 
bitterness on the back of the tongue and a typical Tyndall effect with a little 
laser pen, but not noticeable sparklies ;i.e., bigger particles.