puffer.. i dont know alot yet, still learning like you. in your original pair the one that stayed alive was the smaller right? that would make him a male. males can turn to females , but once female, cant go back to a male
if the fish you bought was 2 inches, that prob. way to big. and if it was alone in its tank when u bought it, it could very well be female as well.
its best to let your clown (that u had oringinaly) get as big as you can (at least 2 1/2) and then by the SMALLEST clown you can, a juvi thats hopefully in a tank with lots of others like it.
When you QT the new baby clown make sure you leave it in qt less than 2 weeks (unless there turns out to be a problem) or it could turn female...
I bought two maroon clowns about 1 1/2 months ago and they were almost the same size. the slightly smaller one got beat up over and over agian, i had to take him back. Ive been reading up on pairing since and it looks like im gonna have a heck of a time since i chose maroons lol