Question: ![enter image description here](https://i.stack.imgur.com/MW1Mt.jpg)

This problem has bothered me for quite some time and I can't solve it. I have even tried to make a construction, but it sometimes tips to the left and sometimes tips to the right :).

When we submerge the body in the water the water pushes it up. That is an action. At the same time the body pushes water down. That is a reaction. So the balance should be maintained.

But, since the water level rises the hydrostatic pressure on the bottom is greater so the right side should go down.

There is another similar problem but it's not the same. 

Please help.

Answer: 
The balance will be maintained because there is no EXTERNAL force applied on left or right side. This is because of the same reason you can't push a car while sitting in it!
So various forces neglected (including gravity, air resistance, thermal forces, air pressure) - but your question suggest this is an inquiry about the effect of bouyancy.

That being the case, lowering the mass into the water brings into effect its bouyancy. This is a force lifting the mass and acting down on the water.
However, as the mass is tethered to the scale the force acting down the string is reduced by the same amount as the bouyancy, and the net effect on the scale is zero.

(Also neglecting rotating frames of reference, light pressure, stress and young's modulus, magnetically induce currents etc)