Dark blotches - phosphorus deficiency?

I have a Zkittlez auto in tupur mix.
It’s 9 weeks from sprout and starting to flower.
Tent is always 55-65% RH and 70-75°F.

Feeding it 2-3 times a day 6-7/gal GO BioThrive Bloom (2-4-4) and 5ml/gal CalMag (2-0-0) in RO water, Ph to 5.8-6.0 and EC 0.8-0.9, 550-650ppm.

Measured the runoff at ph 6.1-6.2, EC 850-950, 550-650ppm.

I’ve had a cal deficiency with it so that will likely be in the photos as well. Now I’m seeing dark, almost black blotches on fan leaves. This is my 2nd time so I’m new but with looking at charts the only thing I could figure is a phosphorus deficiency maybe?

It’s gotten a bit worse over night.

Today’s first feeding I’ve upped the BioBloom to 10ml/gal and Calmag to 6ml/gal at 6.85ph, 1.07ec and 740ppm. Runoff was 5.98ph, 1.01ec and 690ppm.

I get that when my ph is out of whack so start looking at your ph your ppm looks fine but I don't go by runoff I made sure to get a bluelab soil meter copped it for 80 brand new and I love it makes my life easier if its to high I do a lower ph feeding to low etc