dog faced puffers or marine i would not try too put them in brackish water you would have little sucsess puffers are pretty agressive to they also chew up live rock and corals with there beak so they do better in fish only tanks but i have sen them in reef setups .if you are looking for puffers for fresh or even brackish water there are spotted pufers you can look on this web sit www.liveaquaria.com