Hello, I would like to try keeping a Nautilus, in a dedicated tank to themselves. My question are: Is a 75gal aquarium big enough? What kind of decore/Substrate if any? Filtration? Last but not least, am I just destining the animal for death? I would not like to do that, is there any possibility for success? I mean past 6months. If that's all it will live, I would rather leave it in the ocean to live a long happy life rather then in my home for a few months. Thanks!