I finally took out my Blue Hippo and replaced it with 2 Pajama Cardinalfish. I already had 2 Pajama Cardinals in my tank. 1 of the 4 is being very aggressive and chases the other 3. Funny thing is Its the 3rd smallest one. Should I remove it and place in an acclimation box or should I return it to my LFS? Any info on their aggression and what I should do will be greatly appreciated.

