The past day and a half the koi have been docile and swimming in a bunch into a corner. They eat about half of what I usually give them where prior they gobbled it down. The pH is 6.8. The temp of the water ranges between 68 - 70. Does anybody know what might be going on with them?
What about your ammonia, nitrite, and nitrate levels? And have you done anything that might increase light to your tank?
The koi seem to be doing better but still slow moving, and eating better. The pH is 6.4, today, ammonia is 0.5ppm, nitrite is 0.5, and the nitrate is the lowest I have ever seen it since starting a little more than a year ago at 40ppm. No increasing light issues except staying lighter in the evening from the sun. Water temp still between 68 -70. They still do a little corner swimming but not as much. On the 11th I changed out about a third of the water. Thank you for the input.
A few years back some new one inch koi of mine did the same thing. They were grown in isolation until they came to my system and introduced to my tilapia and their germs where they got sick with the "common fish cold". I had to isolate and salt then for a while. After about a week and a half they got better and started eating again. I put them back into the system and now they are LARGE koi. Now if I am introducing new fish into the system I start in am isolation tank filled with system water for a few weeks for observation. If they need treatment it is easy or if not into the system they go.