This is a “bottomless aquarium, ” or it is also called the “antigravity aquarium.” It is a tall pillar of water that sticks up out of a pond or tank, and it gives the fish a new view of the world around them! The video below shows such a tank. The German YouTuber, TChelmut, who posted the video made the tank with glass that was 1 to 1.5 cm thick.
The whole thing weighs 110 pounds without the water! With the water, it weighs a staggering 352 pounds. As you can see, the Koi really enjoy the tower! The air pressure in the tank won’t allow the water to fall. If you were to take the lid off, the water would succumb to gravity and spill out.