George;286620 wrote: I really wish people would stop buying fish that "will be ok until he gets too big then I'll just sell him". It's irresponsible even when you know what the fish is, let alone when you have no idea what kind of shark you're getting from the egg.
You probably don't have the setup necessary to keep it for any period of time. Tank size is only a beginning criteria for keeping even the smallest shark at home.
The advice you'll find here is to take it back to the store you got it from. I understand it's not the advice you want to hear. It's not the "best advice" or "good advice", but rather the only advice open to a responsible aquarist.
You're not the first person to make an unwise purchase. Everyone here has done it and there's no shame in it. The shame is if you could do something responsible to correct it and stubbornly don't.