If plane is heavy on nose (elevator trim is upwards or you must pull permanently), move accupack back.

If plane is heavy on tail (elevator trim is downwards or you must push permanently), move accupack forward.

Moves are in range of 1cm for next flight.

Other situation - you sticked elevator into wing obscuring possition. Plane cannot be balanced, you move accupack extensively and plane lost all of good flight properties or it is very sensitive on elevator deflections. The ONLY reccomendation is meet construction plan.