GSPs, live rock, odl reef tank etc.

[Jarred Darque]

I am considering converting my reef 29 into a GSP tank (1 puff)

can I keep the same live rock?
Will it kill all the inverts? (I figure this is a yes?)
any allowable tank mates? (specifically, I wouldn't mind some form of cleaning crew no matter how small)
soft corals, would it destroy them?
do I need to drop the tank down to brackish before I put the puff in? (I would need to drop it and let die off happen on the live rock since it is in full salt, let it cycle fully then before getting the puff in this case)

[PuffnStuff]

You could just slowly acclimate the puffer to full salt so you don't kill everything on your rock. I saw Nick post that he took GSP's to full salt in I think an hour. No guarantee he won't eat/nibble everything else in the tank. Snails will definitely be eaten as well as shrimp. Could you trade in your inverts/corals for some cash or store credit? My LFS accepts trade-ins. As for a cleanup crew, I'm going to try a lawnmower blennie with my 2 GSP's I'll hopefully pick him up this Friday and begin quarantine. Any crustaceans would be quickly eaten by my puffers, I did have a ghost shrimp live for four days, the other 4 were gone in a day...

[Agnate]

Depending on how big of a GSP you get, you can potentially keep crabs (very large hermits) and a few snails (if they're tough enough to survive - I have a few trochus living with my 3 puffs) with your to-be GSP. I would keep the tank as full marine, and pick up a GSP that is about 1.5 - 2 inches in size. He'll love the salty environment, without a doubt. No point in going through all the effort of brackish when you already have a proper marine setup.

If you have a reef, I would honestly suggest that you trade in all coral (except maybe leathers and mushrooms), as the puffer will inevitably devour them. My Ceylons were even picking at the leather I bought a while ago, so there's no guarantee. I've recently set up a divider, so I plan on trying to keep a few coral in the tank soon enough.

Alternatively, you could look into getting one of the Toby puffers, as they're considerably more reef "safe" (not to say they won't eat anything), are marine fish (thus get along with things a little better), and are also pretty. They still eat inverts, so no change there. I just figured I would mention this.

[Pufferpunk]

My adult GSPs eventually got even the largest hermit. Keep in mind, 30g is the minimum recommended tank size for an adult, so I'd forget about tankmates in a 29g.