My limited experience with canards resulted in a need for "upthrust" on the pusher engine. By that I mean that high engine power will then tend to put the plan in a climbing attitude (by pushing the tail of the aircraft down). This was after initial trials where the plane would NOT lift off, until I killed the throttle - at which time it would leap off the ground. The change in the thrust angle solved the problem. Now this might have been a result of a draggy undercarriage, lowering the aerodynamic center of the plane. I don't know. The plane survived, although had to be rebuilt a couple of times.