Sho Koi Impact
Everyone wants a good fish food when they have good fish. Foods have been manufactured for years which were made for catfish, or trout, but until recently, few foods were engineered for Koi and goldfish. Several years ago, the Total Koi Company (Sho Koi) engineered and began production of a custom made food but this one had an immune stimulant in it. The problem is you can't "see" immune stimulation but you can sure see the growth in these fish.
Cost effective food is well accepted, widely used in the hobby and has the enhancement of Impact Optimun. The convenience of having it delivered to your door is also a plus.