Expert: Eric Mathes - 5/16/2009

Question
I have an outdoor pond, approximately 5,000 gallons.  I have a mix of koi, shubkins, comets in it.  They have been doing very well.  Today, a fish, comet, was a little lethargic and it seemed his left side gill section was dark red, almost blood color.  I went to pick him up, thinking he was dead, an initially, he didn't move, then he started flipping with energy.  I placed him back in the water, only to watch him swim in a tight spiral a few times, then float around upside down, then start to swim in spirals again.  He has since been removed from the pond.  The other fish seem to be fine, but  first, I would like to know what this maybe, second, how to stop it before it becomes a problem.  All water tests are fine and salt level is good.  Please help!  Brett

Answer
Hey Brett it sound like a bacterial infection to me. Watch the other fish closely, if they start showing the same signs you may have to treat it. I don't like treating my ponds because I never have much luck with it but some people do. Make sure the pond is cleaned and the bottom waste is removed. Thanks Eric