Thanks I'm stoked to have him! Im upgrading him to a 9g soon and will keep going up as neededI was planning on keeping him by himself and a decent amount of corals.
Is there actually anything that can be kept safely longterm in a smaller tank? Corals to stay away from? Coral that would be a good fit for his tank?
Right now when he is small anything larger would be OK but in that small a tank you can't really put large fish so it would be best to keep him by himself and as you say upgrade the size of the tank. Keep him well fed ... and as to corals I would only put small ones but to suggest some I would need to know what kind of light you have over that tank (type of bulb, intensity, and K degrees - all would help). Let me know.

I was planning on keeping him by himself and a decent amount of corals.

