I was looking at this eco-aquarium But I know it's common for people to keep fish in tanks that are FAR too small. I don't want to be one of those people. Can anyone recommend any animals that would be comfortable living in a tank this size? Or is this just a gimmick that hurts your pet? I want to do this right and I have no interest in harming an animal for my own amusement. I'm a responsible pet owner so I'm doing my research. So any advice you guys can provide would be greatly appreciated.