How long have they been in those pots? Your soil chemistry just went screwy, evidenced by leaf issues and low runoff pH. I'm guessing they've been in those pots well over a month...?
Water VERY HEAVILY at 7.5 until the runoff comes up to almost 7, and then water again with 1/2 strength bloom food at pH 6.7 to finish the flush.
We see here the major drawback of SCROG... difficulty in accessing the pots nad re-potting if the need should arise.