"Martin H. Eastburn" wrote in message
...
Chlorine gas forms with Water and makes HCL and O2 - Chlorine reacts with
other
chemicals present. It takes some pool calcium and makes Ca2Cl or some
form.
And naturally dissolved gas. It is this gas we smell when we turn on the
tap
or get a whiff at the pool...

Here is an article about chlorine and chloramines in tap water......It is
directed at tropical fish collectors, but it is interesting, none the
less....
http://www.csd.net/~cgadd/aqua/art_chlorine.htm