"itten" wrote in message
...
250 gallons. Started out adding 12 feeders, then 20, then another 20,
then about 10 mosquito fish, 10 goldfish and finally 5 Koi of which I
lost one. I live in SC and the water temp is about 72. My pond water
tested good yesterday. I removed the two railroad ties that I
suspected being the problem. The four remaining Koi seem to be doing
fine as well as the larger goldfish. It seems that I started losing
the smallest of the fish first with the exception of one of my Koi.

I think your problem is probably overcrowding, but I also would not keep the
treated wood nearby. Creosote treated wood is much different from pressure
treated wood, and I would not put it anywhere near my pond nor garden.

BV.