Yes with any conventional configured model aircraft when CG is specified it is always with an empty tank. And as indicated above if you balance with a full tank you will be in most cases (there are always exception such as a tank centered on the CG) excessively nose heavy. If this works for you then fine but realize its not the orginal target CG.

If you think about it its no different than full scale one always starts out with an actual calculated empty weight CG from actually weighing the three wheels and this is required Wt. & balance data for each airplane then you start with this to caculate the actual flight CG for each flight. Which of course must be within specified limits.

So if you think about with our models we balance the airplane at the specified limits and our opportunity to screw things up is far more limited all we really add is fuel and in most cases it will make the actual flight CG a bit forward and safely not rearward. This is another good reason not to balance much nose down, You see that 7 degrees you use means you are balanced further foreard than you think. Seven degrees nosedown would make it difficult to keep the airplane from sliding off the balance rods.

John