I have been using your product Koi Clay as an additive for the water in both our koi pond and water garden. It has benefited the water clarity, the fish and the water plants. After I started adding it in May of last year, within a few weeks I noticed a marked improvement in the color of the koi. One large Showa in particular had lost the intensity of the red pattern. In fact, the red on the head of this koi had faded to a washed out orange color. After a month of regular additions of Koi Clay, we began to see this pattern come back to a brighter red than we had ever seen on the fish before. It has retained the red color and is still that way today. There was also a noticeable improvement in the color of many of the fish in our pond.