If you buy a 50Gph filter, a good heater, and plenty of plants to break line of sight, you could try. but their may be problems.
If you got only one dwarf puffer, you could either buy a few otocinculus to keep it company (although oto's prefer to be in bigger groups) or if you find any Bumble bee gobies that have been raised in freshwater, you could try 2 of those.
Just make sure to do at least two 50% water changes a week.