hello,, I have had my pond up and running for over year, plenty of plants and have a awesome filter system, with air stones in the pond also, I have noticed last couple of weeks my koi seem less active and not eating any advise please
This is an old thread. You should start a new one for better exposure and results.
Give us more details about your pond, fitration, fish, your climate, etc....
We can only guess without more details....
This may be the number one choice of ideas in my opinion:
Your fish might be acting shy because they may have been spooked by something. Perhaps a raccoon, bird of prey, feral cat, etc.
Or they may be stressed due to lack of oxygen, ammonia levels too high, rapid swings in Ph.
A common problem is overpopulation. They may have outgrown your pond and it has reached a tipping point where they are competing for oxygen.
A liquid reagent test kit would help identify any water parameter problems. API makes a master pond test kit. Dont use the test strips, they tend to be inaccurate.