Hello, veteran parent here. I have 5 minions. How are you going to keep him out of it? Height isn't good enough. My fat little 18 month old can get on top of the fridge. She uses the drawers as stairs, pulls herself up with the upper cabinet knob, and uses her sticky little child/gecko hybrid feet to scramble up on top.
I wouldn't put a tank in a kid's room. Not until they are pre-teens at the earliest.
Our children must be related...