[MikeM]

Hudi: You have raised a lot of points. No question that much faster growth occurs with long warm growing seasons, and that affects color. It is often mentioned by koikeepers in cooler climates that rapid growth in shorter growing seasons can result in loss of Hi ... although sometimes I think they may just be giving up too soon ... need to wait for the pigment consolidation to catch up with the growth.

The idea of using chillers has to sound strange to the folks in Britain worrying over virtual year-round heating costs. That's a whole topic for investigation!

That Shiro Utsuri do well suggests that because they lack Hi, color-enhancing foods (like spirulina) are not used with them. But, I'd expect them to be eating the same foods as others in mixed ponds. So, somehow the shiro of Utsuri is not as affected as the shiro of Kohaku and Sanke? Can you share more on that?

The nature of Showa Hi is another whole topic! In fact, there are so many different types of Hi and development characteristics that it becomes very confusing! I think I know what you mean. Today, it is possible to find Showa with just about any sort of Hi that can be found in Kohaku strains. The Hi in older lines of Showa has always seemed different to me ... a soft rosy quality to it, even when very red, rather than orange-based Hi as in most high-grade gosanke today. This is what I'm thinking you are referring to.