Hi,

Sorry but I don't know how to use really good EJS and so I don't know how to use polygone and how to reduce my number of tubes.

I told you that my GUI is like yours because I think it is. If you took yours, [color=red]I just connected the out to the in.[/color] We don't care about the third reserve of water. It's just to better understand how works the project in real.

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It seems that the only differences are dimension of the tube... etc.

Those two equations are the same form.

It seems that what you need is just change the value of variables in the original version.

Why the equations are the same if the output is connected to the input?

I believe the above equations should be modified if the output is connected to the input (a feedback loop).

That is the part which I do not understood!

Do you need the height as function of time graph h(t)?