The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
Brackish ain't full-blow saltwater (SG 1.026 or so) though, right?
Melouse58 beat me to it though - even if it did make it, that puffer would have fun with it for a few days I think before it ended up as a feeder fish.