introducing new fish.What do I do? I have a blue and red guppy. I introduced a smaller yellow guppy and two tiny barbs and my original guppy's tail now looks as its been bitten. I' ve watched them and appears that the new guppy is biting the old.I don't know what to do, but i am going to the pet shop today to ask. Should more guppy's be introduced to even it out???