Originally Posted by: ddiddlernow I have to decide if I had 5 strings down an octave.[/quote]

[br]That's where a set of aural pitch pipes we used in days before long ago smartphone apps or piezo/aural headstock tuners were a boon. Before very long the pipes being unneeded other than for confirmation due to astonishingly rapid assimilation & identification of the reference pitch note purely by ear, consequently tuning the others by the relative tuning method. You can still buy pitch pipes inexpensively by the way.

[quote=ddiddler]I can place my fingers under all the strings at the 12th fret hmmm

If I'm interpreting what I'm reading accurately, then you must have very [u]very[/u] tiny skinny fingers, or your guitar's action is absurdly high needing a truss rod adjustment and possible attention to its nut, & possibly at the saddle/bridge.

Assuming a steel acoustic and not nylon classical given your reference in a previous post to string gauge rather than tension, did you remove and (perhaps errantly) reseat the saddle during the string change process at all?

You shouldn't be able to fit even your pinky under [u]any[/u] of the six strings at the 12th fret with action set to standard reference spec.height. Something isn't right if you can.