Brown spots on leaves

[Mazzariman]

I’m getting some brown spots and skightly curling leaves that turn crispy. Not all plants/strains are displaying this. PH is 6.5 - 7.3 (approximately). Outdoors, good morning to noon sun with filtered sun and shade the rest of the day. My soil is a primo mix of Happy Frog potting soil, coconut husks, perlite, no large chunks of lumber, worm castings, and homemade compost. 5 gallon size containers with good drainage and I only use fish emulsion, and Big Bloom (Fox Farms). If it is a deficiency, I don’t know why all plants are showing this. Maybe strain related? It does seem that those affected are very similar in their traits/characteristics (Indica dominant) I’ve been just flushing with pure water to rule out my supplements. Any thoughts anyone?

[CaptainWiese91]

PH fluctuations is my guess.
You’re Ph is a little too high in the range.
7,3 it’s going to struggle so absorb nutrients

[Mazzariman]

Thanks Captain! I actually meant to say that all other plants aren't showing this instead of are. Very strange. I will look for a digital tester since mine just gives ranges and I'm guessing on the over/under. New growth seems fine so far.