So everywhere I have read up about corys so far says that they should be kept in larger groups (at least 3, but 6 is better). Does this mean one must have 6 of each type of cory, or will different types of cories feel happy with each other. So say, for example, if I got one pygmy cory, one panda cory, one albino cory, one bronze cory, one bandit cory, and one peppered cory, would they school and be happy together, or would I have to get more of each species?