Help identify this deficiency please....

I suspect magnesium deficiency but am not sure. Been pushing cal mag but she is not getting any better. Running dwc on AN 3 part nutes. PH 5.9, PPM under 1K, day 29 flower since the flip. Room temp 76, RH 60. 600w HPS. This NYPD is the only one of 8 having an issue. Pic links are broke in the check here 1st thread so I am turning to RIU growers. Thanks in advance for your help. The girls are stacking up nicely and want to avoid stressing them....

looks more like zinc def with the brown tips ?
try raising your ph a little

Did rez change, ph'd 6.0, ppm 725. Still no change. Happening from the top down on the older leaves. Day 38 flower. Running AN ph perfect line, Calimagic and koolbloom liquid.

Got a pic of the whole plant?

Yeah That does look like zinc deficiency.