did you do any kind of physical on the dead fish? look at the gills, feel the slime
coat? it is really impossible to determine what the problem is. you are in
California, which means your pond could be quite warm. flukes are more of a problem
in warmer water. aeromonas and costia in cooler water (IIRC). in teh waterfall
points towards a gill problem. bloated sounds like dropsy. ah well. Ingrid

joe wrote:
Had a Koi die yesterday. I noticed he spent a lot of time in the waterfall
and he did seem a bit bloated. At about 4:00 he ate with the other goldfish
(alas, the blue "herring", got the all the other Koi ). At 6:00 he was belly
up. I've checked my levels and all are way fine. None of the other fish seem
ill. Joe in San Diego