Out of curiosity, why did you cut the Ca out of your equation when you suspected it was short?...and it appears from your pics and description you were correct in that assumption.
This also happened last grow with a different strain,I used calmag start to finish on that one.
Perhaps I was using too much as this round its not as bad.
Ill re load and see what happens.
This plant is in a 5 G rdwc bucket,the other half of my room is in top feed hydroton,in a tray.Same nutes same res.
The tray side is much lighter in color ,there also a mix of 2~4 weeks behind.
Ive dropped N the last 2 weeks ,almost in half.So 4 ml/l bloom ~2 ml/l N .
I have hard water,170 ppm.When this first started I was using calmag @1ml/l.Perhaps Ill try 2ml/l.
edit to add the tray side hasnt show these def yet.