I recently got 3 bleeding heart tetras and everything was fine for a couple of days then i notice my two male guppy's fin were just all tore up. Now today i've noticed that both of my dwarf gourami's have some nips in there fins. i know its the bleeding hearts doing this, everything was fine before. Are they doing this because there's only 3 of them? i was planning on getting at least 3 more but i don't want to end up having a bigger problem.