Hi Dick,
The main reason to my question is curiosity. The question of water perameters are always asked from one hobbyist to another, to find out how and what the effects are from pond to pond. I have noticed that here in the States that koi have a tendency to not meet it's full potential both in size and quality. I know that the water source from our cities differ tremendously and affects our koi differently as well. I believe that all the water changes in the world won't make the difference because of what our water source has to offer. So my question is, what makes the waters in Niigata so different from the waters here in the U.S.?