Welcome to the forum! Ah the joys of a youngin' BP!

He might be a little freaked from the 20g, not sure though. He seems to be decent sized, just make sure you have the tank set up properly. IE, Cover up 3 sides with something dark, and either put balled up newspaper in there or buy some fake plants and put them in there. Newspaper is a great substrate!

He's a cute little BP, you'll enjoy him!