A fluid height backpressure system includes a printhead, a fluid supply tank, a backpressure device, and an air removal device. The backpressure device responsible for supplying system backpressure includes at least one tower disposed in an upright position and having a plurality of walls defining first and second chambers for respectively communicating with the ink supply tank and a fluid supply reservoir of the printhead. The air removal device provides additional back pressure in the second chamber, allows backpressure in the system to be maintained even with an empty fluid supply tank, and also supply of ink to the fluid supply reservoir of the printhead substantially without air bubbles being introduced therein. Also, ink sensors are utilized for sensing out-of-ink/ink-low conditions and also to help establish and continue the operation of the backpressure device.