It's an idea, and one that I've been dreaming about of for years. I've sketched-up similar tanks to the one you posted. My problem is where would I park a 20 to 40 foot shipping container or an aquarium of that size. In a pole barn? Nice if you already own one. Otherwise there would be additional costs to building a shelter with electric, heat, air, and running water for a tank of this size. Personally, I'd need a budget of at least 200K if I were to do this myself. Even If I could buy the property and get the building permits, I'd have no time to build it myself because I'd be too busy working at my job trying to pay for it all.