During feeding Thursday night, I noticed one of my Koi, the largest and usually most aggressive eater, not eating. Same behavior was noticed at the Friday morning feeding. In addition, I saw a light brown scaly like patch on his side. Friday night, I removed him, gave him a salt bath and put him into a rubber tote with an aerator and medicine (Melafix by PondCare). He did not survive the night. I do not know if my actions to save him, ended up killing him or if he was destined to go that quick anyhow.

Sunday night and Monday morning, I noticed another fish not eating. I do not see the same type of patch on this fish, but I do notice a bit of swelling, about the size of a quarter. I am reluctant to give him a salt bath and quarantine it the same way, since it didn't work out so well last time. I do not know what the cause could be.

PH is 7.5, salt is good, ammonia level is good, water is clear, there are some plants, filter runs 24-7, basket is clean, filter pad is clean, bacteria was added.

The pond is 1 yr old and these fish are also 1 yr old, except for one that was added about 6 weeks ago. All the rest of the fish look and act fine, but so did fish #2 until Sunday.

The only thing I think may attributed to a sickness, may be that I added 3 small Koi to the pond 1 month ago, 2 weeks later, 2 were dead and I never saw the third one after putting it in. I am not sure if they were sick and I am not sure if they could of sickened the others two weeks after they died.