i have 2 dwarf gourami's in a 30 gal tank. one of them is agressive as hell. always swimming to the other side of the tank to nip at the other one. he will constantly try to bully the other gourami. also i see that the one getting bullied has nips in its fins. should i take the agressive one out and replace it with another that maybe might not be agressive? thanks for the help