How are you testing ph of the soil? (most soil ph probes are inaccurate pieces of junk)
How are you testing the water?

Have you tried running a cup of ph'd water through a pot (gallon) of your soil soil and see what the runoff reads? (only works with a ph pen)
You might be chasing an erroneous ph number, and as a result, might be adjusting ph out-of-range.

I grow in the SW desert where my growshed temps are scorching during the summer. My daytime temps top-out around 100 to 105 degree range throughout flower...with the a/c on. Humidity is virtually always in the low teens, except for the occational monsoon conditions. Been growing under these conditions for the better part of...IDK...7 or 8 years? A link for handling heat is in my signature.

I generally grow Indica's and Indica dom's in summer, sativa and sativa dom's in the winter. My indica's handle the heat better than my sativa's, but am able to bring either to the shed if necessary. :thumbsup:

How long have they been on "light" nutrients? Why...?