As a parent, I see their point of view. My son has a turtle, and 40 gallons is the max I'll let him have in his room. I was the kid that had a tank break on a 2nd floor bedroom. Thankfully, that was only 10 gallons. I was also the one that had a 55 break a seal in a rental apartment. The good news is that one day you will have your own place and be able to get a bigger aquarium. In the meantime, seek out fish that can be happy long term in your tank.