Mistey illness affexting my fish

[Bradonarias]

Hi i need h hi I need help for my face is because there appeared to be bleeding from the fence and I don't know what what kind of cheese at and I just need help because they just laying down then they don't want to do anything and I'm scared I might lose him and have several go fishes and like four koi in my 32 gallon tank and I just recently clean the tank so I need help so please i will love advices

 

[the loach]

What are the ammonia, nitrite, nitrate readings? How long has the tank been set up?
You know that both goldfish and koi grow too large for an aquarium right?