It is cool looking, but with any failure in the system I would not want to be the one cleaning up the mess.

Yes but I would be concerned about eventual oxygen depletion from recycling the air. Although there may be enough gas exchange from the 'open' areas of the tank.

Go
 

Depends on how the tank is setup, it wouldn't be a big mess.

If you fill up the bottom tank, setup the vertical part, and vacuum the vertical part, you basically guarantee that if it fails, all the water would be sitting in the bottom tank. The water probably wouldn't splash either because of the vacuum that has been setup at the top.

If the vacuum is stable, it technically will hold, since the only way that water will get out of there is by new air coming in. And basically as the new air comes in, the same, small volume of water water would be pushed out.
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CD175

I think that's exactly what's being done for this aqaurium.

Interesting ... I bet that's it. I was thinking it was maybe a panel of glass separating the air curtain from the vacuum side but I bet you're onto something there. A "closed loop" but for air instead of water. :lol:

Yeah that's what I was thinking but you would need one hell of an air pump. That tank looks 4 feet tall, that's a pressure of 4 feet of H20 the pump would have to overcome. And I think it would have to be more along the lines of a venturi as an air pump wouldn't last too long with the moisture and humidity it would be exposed to in this situation.

I guy could probably use a float switch to activate some kind of vacuum system when the air pocket got to a certain size.

If you look at the top of the tank he has a line drawn at the fill point of the waterline.

I also think this is done wiht mirrors. one scene the fish are in the top half then it cuts and they are all in the bottom. then when they swim under the top part they disappear. you can clearly se the top has a bottom pane of glass.

Tank
 

http://www.youtube.com/watch?v=Z7tq4LRurMs
This shows how the tank was built. No tricks, this works.

That's exactly how I think it works...and that it was very clever to come up with it.