I had 50 gal with puffers back in high school. Lasted about 4 years and then everything died.
Only about 2 years ago did I find out from a mom-n-pop that most puffers put out a poison that kills everything when they die.
Shame. I had figure 8's, spotted, had one about 1 & 1/2 inches around and about 3 long (fresh water) and some black mollies.
First one died and erased the tank.
Still enjoyed them more than any other fresh/brackish fish...