Leaves look like they are "canoeing" which is usually a sign of a ph problem, causes nutrient lock out. High heat might make it worst.

Keep in mind that heat has an effect on ph, most calibration solutions have a chart for temp compensation, your readings may be off. Especially if you calibrate indoors in ac then read 90 degree stuff outdoors.

Not sure what to reccomend, I might try adding some dolomite lime to the soil around the plant and go alittle higher with the water ph.

Wish I could be more helpfull, tho I'm sure someone else will chime in.
Good luck with it.