I bought 3 dwarf p-uffers and my one just killed my guppies. I don't know why this one has decided to attack my other fish!! my other two puffers are always nice, but this one isn't!! I was thinking of buying a little 5 gallon and putting the 3 puffers in it 3 ghost shrimp and 1 otto. Would that be okay? it will be a naturally lookign tnak with live plants, mostly hardy plants like java fern!!