Most brackish puffers stay within 3"-8", starting off with a one figure 8 in a 20 gallon would prolly be fine. They're pretty hardy too. Have you had any experience with brackish fish before? Fahaka puffer are really nice, but they're beasts and would be more suited to a 75 gallon imo.
Sorry Robert, I've been meaning to ask you where to find those articles again, as I lost all my favorites w/my last computer. I checked in Aquasource/Archives, but couldn't find them. I've got them now!
Pufferpunk - the Archives are fully accessible again, but have not been updated as yet, so there are 2-3 issues that do not appear in them. I finally got the URLs for all my articles, but not the other gaps.
just thought I'd put it out there that if you're not ready or prepared to take the "brackish" route, you can also find that there are a few "fresh-water" species of puffers out there too.....