Everything I've read said cherry barbs are very peaceful and not fin nippers. So I finally went to purchase my 29 gallon tank today (just got it all set up) and the lady at the fish store told me that cherry barbs are semi-aggressive and fin nippers?! Is this true? I was planning to use them as my starter fish - since they're hardy and beautiful - but she said they'll terrorize the tetras that I plan to get later...