Mike Snaden's site is
www.yumekoi.com He has a tremendous amount of knowledge about both water and conditions in Japan. I will try to dig up the old articles I learned about the cobalt and pigmentation from. It might take me a couple days, very good reading for those interested.
I went today to buy more bulk food from my supplier, read the contents on the bag, and sure enough the third to last ingredient is cobalt carbonate. I do not htink it is always last due to it not being important, but due to it's cost. It always winds up in the last few ingredients listed. The only exception I have ever found in food is a particular brand of parrot fish food that had it in the top 4 or 5 of ingredients. I cannot remember the name of the brand.