I've tried to get the tension as close as possible but i'm using the hand-squeeze method - not ideal so it might be out. And yes, I thought the wheel could have been buckled previously (it was 2nd hand)
Will attempt tightening beyond what seems comfortable; then LBS. Cheers.
Is the tension the same than the other spokes? It may be an out of shape rim that you're compensating with more tension, or just an uneven build.