What is the the height H of the fountain?

Question

Three half-full water tanks are connected with pipes as shown here:
http://i7.tinypic.com/6gdvqdv.gif

The numbers on the right indicate elevations with respect to the floor (ignore viscosity and other losses)

Answer 1

Fuller explanation. A pressure head of 150-20=130 cm is applied to water at 100 cm height. This water rises to 100+130=230 cm. It's not a perpetual motion machine because the 130 cm head could be transferred to another container at any height. And for each Δm of water that flows from the top tank, the PE loss of Δm*130 is balanced by an equal PE gain in the flow from the middle tank.

Answer 2

Maybe 230cm.