Keep in mind, you can always buy a tub right now.. and keep the tank for later when he has put on some size.. When I first got my little guy I had him in one of those shoebox size tubs and I have just recently upgraded him. I recently went to the post office and grabbed a couple of their small mailers for hides, Damian seems to enjoy them.. Also if you insulate three sides (if you have not done so yet) with foam board or something similar it will help to trap the heat and provide more security for him.