I have a 30 gallon tank that I have not set up yet,I would like to have two or three puffers when I do set it up,what types of fish are compatible with puffers? I have heard that puffers are aggressive. I was also wondering if I can also have a few plecos with the puffers as well as knowing what other fish would be safe and compatible. Also how often do the puffers puff out and how big do they get when they puff?