Until recedntly I hadn't smoked in 25 years. Now I hear about schwag, mid, haze, afgan, high grade and all kinds of other stuff I don't know about.
I do know that what I smoked, as described above, was "marketed" as mid to high grade... a single hitter would get me high, two in a row would definitiely render me useless for a couple hours... so that is why I usually only smoked two or three times during the day. I really liked it. I know one can not determine exact THC content without a test but does the 30 day rule of thumb apply to this "mid" quality smoke?