Is fuel balancing done automatically?
The A320 has an auto mode that will do the following:


Center tank will empty first.
The inner wing tanks will empty until they reach 750 kg in each.
The outer tank transfer valves will open and remain open allowing fuel to flow to the inner tanks.
The center tank pump will stop 5 minutes after low level is reached and remain stopped until the inner wing tank reaches the underfill sensor (approx. 500 kg) at which point it will restart.


The center tank pumps can be switched to manual mode.
The wing tanks can be turned off manually.
The cross feed valve is also operated manually.

source: A320 FCOM