I culture daphnia in two buckets outside. Other creatures have cropped up, including ostracods. The cultures are running just fine. I honestly haven't looked close enough to determine whether there are copepods in them, but I'm guessing there must be.
If you're concerned, raise some daphnia alone and then raise a mixed batch. There's no better way to learn than through personal hands-on experience.
Do you plan to raise them indoors? I know a lot of people do that with success, but I tried and found it to be more work and effort than I wanted to deal with. It is surprisingly easy to raise them outdoors, although I obviously have no access to them through the winter. Their numbers will explode and crash in cycles through the summer, but you'll always have enough if you run more than one culture at a time.
Good luck.
