I cant see your pic sorry but when i first started i had a $100 ph metre which was inaccurate and caused alot of confusion. To solve my ph issue i went out and bought the bluelab combo metre (like $300) and followed seymours technique and didnt have a problem after that.
Also i dont foliar feed so i cant answer your question regarding that sorry.
From what has been explained to me you need a ph of 5.6 - 5.7 during veg and 5.8 - 6.0 during flowering.
If your using a resurculating system u will have ph fluctuation and not really know where its coming from which is why i use single bucket.
I suggest head over to seymour buds grow journals and have a read through those, he has some pretty good ph information on those and im really just telling u what he has said.