on the embraer 135/145 we usually use 600kg ballast fuel on positioners only. were not allowed to use ballast fuel to trim the aircraft on pax flights. its shown as a service weight adjustment (+600/+1.0/bal fuel) and is not included in the final fuel figures.
ie captain wants 2400kg inc ballast fuel so 2400 - 600 - 100 (taxi) = 1700kg take off fuel shown on loadsheet.