> The only symptoms that I see are the Rainbows swimming at the
> surface gasping.
Sounds like gill flukes to me possibly. It wouldn't do you any harm to
treat them as it is fairly easy with commercial treatments. Although,
you shouldn't go treating for gill flukes willy nilly as they tend to
develop resistance. The only other likely thing that it could be is
oxygen but given your circumstances this sounds less likely. Does anyone
know if salt will kill flukes? You could always try 10ppt (10g/litre)
salt (cooking [Oz language] or pickling salt [in yankee language]). I
think the commercial cure would likely be quicker though.
Tootles
Peter J Unmack peter.unmack at asu.edu
---------------------------------------------------------------
DESERT FISHES RULE: To boldly thrive where no other fish can make it!
Check out the Australian desert fishes pages at
http://www.utexas.edu/depts/tnhc/.www/fish/dfc/
just click on the Australian portion of the map