Is my plant experiencing cal mag lockout?

Now that you have flushed to remove nutrient lock out you need a good bloom fertilizer

https://www.growweedeasy.com/cannabis-plant-problems/phosphorus-deficiency

Older Fan leaves indicate a PNK Deficiency first mag call would show Up on new growth first

Thanks guys, my pH meter says 7.4. 😳

My guess ; You overfed with nitrogen a bit, they stopped drinking so fast and so many, you kept watering them, that changed pH of medium and further troubles started. Now it's calcium issue too. Wet/dry/wet/dry and watering with good pH. They are almost at the end, I would just try to finish them right Would slow down 50% feed charts too for first few feeds.

Hello there, your plant looks like isn't taking the nutrients properly wich makes her eat their leafs in order to get them. The is due your ph being off.

manganese deficiency from lockout, either from ph out of whack or too high an ec level

I would check the ph of your run off as it looks like you got more than one deficiency going on and that is usually nutrient lock out often caused by ph imbalance 💚🙏

looks like potassium deficiency and may be nitrogen lesser deficiency as well: https://loudclouds.co/wp-content/uploads/2016/07/marijuana-deficiency-chart-jorge-cervantes.jpg

You've got some severe nitrogen issues there and probably a badly-out-of-whack PH... What is the ph of your runoff? You need to get it between 6.0-6.5 if you're growing in soil which it looks like you are... She's in flower so not need a lot of nitrogen - if you're giving any grow nutes, cut them out and up your bloom nutes. Your diary doesn't give any info on the kind of nutes or the quantity you're giving so this is really just a stab in the dark... Good luck!