To see the fish in question, I have on my koi web page...
Gallery of Koi
...the first fish on the page (kohaku) is one that I would like to improve beni...
...The fish I am looking for growth is third down, the showa...
Having heard many opinions here, I wondering if I need to set up a second small indoor pond (maybe in garage?) where I can keep very warrm and feed the one(s) I want to grow, and the larger pond I can keep heated at a much cooler temperature (like 52-54 as suggested) to see how colors develop.