Have you confirmed the species of the puffer yet? Until we know the species I cant really help, as I dont even know if it is freshwater or brackish. Most of the species it looks like are larger and solitary puffers, which would require 40-1000 gallon tanks and nothing else being able to be housed with them. I will say generally when dealing with any puffer, water quality is very important, and having them in an established and already cycled tank is mandatory. Most puffers require live or frozen foods, and snails. Is there anything more specific I can help you with regarding your puffer?? Once we know the species for sure, research can provide us with most all we need to know for its care and needs. I hope I can help.