automatic or python water changes

>From: Jonathan_Kirschner at Energetics_com (Jonathan Kirschner)
  My question concerns
>those "automatic water changers" I see advertised and in the
>catalogs (some of which are probably not so automatic).  I haven't
>found much in the archives about them.  Do they have a built in
>dechlorinator or activated carbon? ....

I, too have questions about water changes with these methods. I'd like to
use a python to both take out and add water but if one does that, how do
you prevent chlorinated water from getting into the aquarium? If the pH of
the tap water is a lot different than that of the aquarium, how does one
adjust that? What do people who use these do?

in Vancouver