Don't know if anyone has suggested this yet or not, but there really isn't much going on with the actual store itself... So how about you can purchase new store locations, start a franchise, or at the very least move to a different area in the mall which could have more room for more tanks, better customer traffic, that sort of thing. After you get a few of the magic fish, the game becomes extrememly boring as you have a retarted amount of money to throw around, so why not atleast soak up some of that extra cash with a new store venue?