One of the nice things about Daphnia, once you have a culture going, you can feed the daphnia paprika (and other things) and thereby enhance the color of fish. And if you use greenwater for the daphnia, you also can get 'green' into the fish as well. Additionally, when you have new, or difficult fish, having a continuous, in their tank, food source available helps fhis eat, and perhaps prosper than if you are only putting bbs or mosquito larvae in once or twice a day--and larval transitions are not fun if you feed and >they don't all get eaten.