I've only seen aquariums mentioned briefly in one other post by the user "Dog". I mentioned this idea in Lee's stream and he and a few others thought it would be cool. I'm an aquarium fanatic so having aquarium options as well as your choice of fish and aquascaping would be a huge enjoyment for me and seems like it would add more customization to the apartments. This would be a separate little customizable space that players can make very unique. It would also be cool if the fish could have very simplistic AI so that it isn't just a loop of the same behavior over and over, they may go into a feeding frenzy and/or have random schooling patterns, that sort of thing. Of course you would want to keep them realistic in design though, for instance you wouldn't make a 6" Zebra Danio or make a Kuhli Loach swim slowly in the mid level of the aquarium and be aggressive to other fish or have a saltwater fish in with freshwater fish, etc. etc. I would be happy to help with those details and include images if needed.