I have a 55 gallon tank with the following fish 2 Pink Kissing Gourami 2 Blue 3 spot Gourami 2 Tiger Barbs 2 Beta Sharks 2 Plactamous (sp) (catfish looking guys bottom swimmers) 1 algea eater 2 puffer fish Recently I noticed the 1 of the 2 blue gourami, both pink gourami, and both puffers have been fin nipped. Which of these is most likely the criminal? Someone told me if I kept the water warmer they would be less likely to nip. Is this true? Help!