Hmm ... I lost one of my baby koi last week, it had been somewhat lethargic for about a week. Others seem to be ok, although I stare at them all the time, worrying about them, since the water is still so murky looking. Did about a 15-20% water change yesterday, and this morning don't see any change in the water quality. I have stopped feeding, and was only feeding when the water temps were above 55, and that was not for very long, but worry like you that I started something I should not have. Last that I was feeding, it was only 2X a week. Water temp yesterday a.m. was 53. Not going to feed them until really warm temps come back, and look like they are going to stay.
I have company coming in from out of state Memorial Day weekend and the 2 weeks after that (sister and niece, then daughter, then Mom and her boyfriend), so sure am hoping things get cleared up by then! That will be a full 2 months after it went murky.
Keith, do you have plants in your pond? I thought you did, and wondering about how much salt can be used and still safe for the plants?