I received a couple of fair answers to my question, but I may need to add a bit more info to the original question. First, the koi in question is only about 6 inches long and has lost all of its red in a matter of 2 1/2 months. It was shipped from Japan to California, where its first picture was taken. A mere 4 weeks later, it had lost 1/3 of its Hi or red color. In the 6 weeks that I have had it, it has been in an established pond, with plenty of algae, good sunlight, good water quality and filtration and is fed high quality food as well as brine shrimp. All of the other fish in the pond are growing well, as is this fish, although nothing amazing or anything. The other koi are all getting more color…my biggest one is only about 13-14 inches, so most are still baby’s, as is the kohaku.
I have tried changing to color enhancing food, which is working great for all the other fish, but this one looks like someone had painted on the color and it has washed off, from tail to head in a steady progression! I would not believe that it was the same fish I got 6 weeks ago if I had not witnessed it with my own eyes!
I realize that koi loose there color eventually, but it usually takes a long time before the color stabilizes, and they usually keep the stable coloration for a good while before they start loosing it. At least, from what I have been able to find in the library, on the web and from experienced koi keepers in my club, that is the normal way of things. But in this case, we are talking about a very young fish loosing all of its color. All of the other koi that we got from this dealer are progressing very nicely. The sankes underlying sumi (black) patterns are starting to come out nicely and the showa is changing, but still vibrant and show quality. That is why I thought that perhaps it was something that some kohakus do in early life, and that the Hi (red) might come back.
I appreciate the help so far, though. Unfortunately, I am already doing all of that and nothing has made the slightest difference, each day, more and more red was gone until now, it is all gone, except for a slightly pinkish hue.
I will keep looking for answers, here and elsewhere…and I will let you know if I find any answers to the question, in case someone else out there has the same experience and can get some solace in at least knowing what is going on.
Thanks. Kathy P.