HELP!! Porcupine Puffer might be sick.

[Borderjumper]

this is just from my personal experiance, but its like buying a fish in a bubble.. its been in basically sterile water.. and I take it home and put it my healthy, but far from sterile tank. I think its ok in your personal tank cause the fish isnt being re-homed, but IMO it lowers a fishs resistance and if that fish is moved into a new enviroment that is not as sterile.. its going to be exposed to stuff it has no resistance to.