Who Gives A Fish Forums

3 days isn't long. Some Bettas take a week to adjust. Keep an eye on him, but don't stress too much. If he's not eating by day 7, then worry.

I'm curious, is it even possible to keep a puffer in a small tank like 30g, or am I just being optimistic here? I'm guessing it's a no-go, but I'd love to hear your thoughts, experts.