cool, and thanks for your quick reply! i just checked under the leaves and all looks mite-free. i've raised the EC from 1.3 to 1.6, so hopefully i'll wake up tomorrow not to find the girl burned! interesting point about the water...perhaps it's not a coincidence then that the spots showed less than 24 hours after the last change?

finally, and this may be a weird one, but the leaves with yellow spots are the ones facing the full brunt of a desk fan...the leaves on the other side of the plant are simply gorgeous! the tent i'm using has, besides the desk fan at the bottom of the unit, a basic intake-outtake fan setup...

do you think I should prune the spotted leaves, or just leave well alone?

all best and thanks for your advice and experience!
jash