Mixing puffers has never worked out for me and I know several other people that have tried and succeeded for only a short period of time. I have had dogs and porcs in the same tank and even when the porc is half the size of the dog they will often nip at eachother and it only worsens with time. Porcs are really aggressive eaters so they will tend to go after any and all food in the tank. This means that when your sharpnose heads for the same food it will most likely arrive at the same time as the porc and in turn be bitten. Porcs leave nice little bite marks. I would move the sharpnose to a different tank if you plan to intro a porc. May work while they are little but over time, IMO< the porc will get less tolerant of the sharpnose. The bigger they get the more problems you will encounter. I have not had experience in mixing these two puffers but have found that puffers in general do not mix well, even with the same species unless they are a breeding pair that is comfortable with eachother and kept in a larger tank than a 72. Pufferlover, what do ya got to say.
