Do any of your fish ever disappear for a few days, and then reappear one day as though nothing ever happened? I have a completely white koi that is about 8 inches long. I think he is called a platinum ogon. Anyway, when I feed and he is around, he comes up and eats just like all the others. But sometimes I don't see him for days at a time. I have a 2000 gallon with lots of cover for them to hide in, so I guess he could be anywhere. It just seems like odd behavior to me.