Hello and welcome! Please post some pics! We love to see pics!
Agree that you might want to double-check your water volume (what are the dimensions of the pond, and how deep is it?). That volume of 1400 gallons is great for goldfish, but not for koi.
What kind of filtration do you have? Based on a question you asked in your other thread, “how does ammonia get out of control?” you might want to do some research on the nitrogen cycle of ponds. It’s the most basic information every pond owner (with fish) should be familiar with. Also, get a liquid water test kit (like API) and learn how to test your water. This will help you understand the relationship between the fish and having healthy water.