Finally I think I got it !

[AB Hammer]

wizkycho

Yet another interesting pump idea. But what is going to operate the valves? I don't see natural reaction being able to do it as easily. It looks to me by your drawings that you will need a shift system for the valves and they will be under pressure remember this.

[wattsup]

Also the water from tube at V2 should not fall through the atmosphere before it lands in the bottom tank because it will create air bubbles. Ideally that tube should also go to the bottom tank and both V1 and V2 should be located in the bottom tank, underwater so there is no possibility of air infiltration.

On a scale from 1 to 10, I would give this idea an 8. You will still have to work out the friction from the seal on the 100kg weight. 100kg is too heavy anyways. Also working the valve operation could be by string connected to the 100kg weight and pulleys. But it is a good idea.

[AB Hammer]

Also the water from tube at V2 should not fall through the atmosphere before it lands in the bottom tank because it will create air bubbles. Ideally that tube should also go to the bottom tank and both V1 and V2 should be located in the bottom tank, underwater so there is no possibility of air infiltration.

On a scale from 1 to 10, I would give this idea an 8. You will still have to work out the friction from the seal on the 100kg weight. 100kg is too heavy anyways. Also working the valve operation could be by string connected to the 100kg weight and pulleys. But it is a good idea.

Greeting wattsup

I don't know why I didn't see that. Very good observation. I guess being sick has dulled down my scenes or I am just getting old. LOL  A top air release device is going to have to be added but that will be tricky for the need of the vacuum to lift the water. I like my design better. LOL 

[sushimoto]

Also the water from tube at V2 should not fall through the atmosphere before it lands in the bottom tank because it will create air bubbles. Ideally that tube should also go to the bottom tank and both V1 and V2 should be located in the bottom tank, underwater so there is no possibility of air infiltration.

On a scale from 1 to 10, I would give this idea an 8. You will still have to work out the friction from the seal on the 100kg weight. 100kg is too heavy anyways. Also working the valve operation could be by string connected to the 100kg weight and pulleys. But it is a good idea.

Hm not sure about the air bubbles.
In relation to the 100kg weight,
the bassin in the drawing must be 100inches (2.5m) in diameter (?).
Do you think, that air could travel about 100inches under water,
before it gets sucked in on the other sides bottom of the bassin?

[wattsup]

Everything will be relative. If you have a 2.5m dia. tank, then the top tank with the weight will be big also, and the filling of the top tank will require alot of water movement that will be relative also. Air bubbles are made in all sizes, some big but also some very small that can stay suspended and enter the riser tube. Also, if this is outdoors and you want the device to be wind proof, I would still put that tube underwater.