The most popular red color enhancer vitamin for all kinds of red fish. C.R. 6 # will increase red color to all red fish, such as arrowana, red gourami, oscars, red discus, gourami, gold fish, carp, etc. Fish will eat and grow well. C.R. 6 can be used on breeder fish without any side effect. This product does not contain sex hormone and results can be achieved within 7 days.