probably better alone to be honest
I have one on itsown and it seems to get on better than when I had another as they used to bicker a fair bit which led to the others demise I suspect
Simon
oh and welcome to the forum by the way
do you have your puffer in brackish water?
Thank you!!! And yes, it is in brackish water. It was a surprise because I was not told at the store it needed it, but it is all good now!
Something which immediately jumps into my mind, perhaps unneccessarily, is how rapidly did you introduce the puffers to brackish water at home and how brackish are you keeping them?
Have you contacted the store to confirm the tank conditions they were in before you bought them?