I was playing today and trying to wrap a bridge around a tank. When i went into zoo guest mode, i landed on the floor and when I looked up, I had this image in my head. So I tried making an indoor aquarium, and it worked! All you have to do is place your tanks, put down a floor in between the tanks, and make a roof with the bridges, and since the bridges snap onto the tanks, it fits perfectly. The only thing you may have problems with is putting restrooms and stuff in your building, but you can fix that by raising the height of your roof. I'll put in some pics once i figure out how to upload, and I'll try to upload the zoo that I made so you can have a closer look.