please when posting koi or pond problems , make sure your post covers the following !! as it will help us to help you

1) All water parameter readings (current readings)
2) give details of your set up ,"gallonage" filter system " pumps make and model"
3) length of time the pond has been running
4),Also include info on any new fish
5) stocking rates (number of fish and sizes " aprox")
6) any recent changes to any of the above)
7) include tap water readings
8 ) try to include pictures if the problem is koi related ie: sore's scuff's ect .

steve