Hey friends let me start of by saying I bought these balloon mollies last Saturday and they are extremely agressive not to mention they already killed 5 guppies and I feel sad. I am a fish lover and it hurts me to see how a fish kills another I can't stand this! Now my question is can I take the 3 ballon mollies I bought and exchange them for 3 guppies. Has anyone tried this before. Please write anything you may know. By the way I keep my fish in a 20 gallon fish tank and I only have 3 balloon assorted fish, 5 guppies and one snail so I know I'm not over stocked. Thanks for the help :l