A lot of the time the damage has already been done but you can rectify that on the new growth, if I were you, I would hold off on the watering with calmag, or watering period until it needs another watering, possibly a day or two until the top inch or so of soil gets dry, and then flush again with the magical cal mag at around 6.0 pH. You can also do a foliar feed of the calmag today and observe the results too. The fact that it has slowed tells us that you're on the right track man!
One question I have is do you know how many lux or PAR is shining down on these girls? I just realized that I was bombarding the plants a while ago and due to the light stress they showed yellowing in some higher areas on the exposed leaves with yellowish kinda burnt ends going into a tip, and it might be my imagination, but I took another look at your plants and they looked similar to mine at that stage last year, some of the taller leaves were a bit yellow with those tips, but some of the lower ones also have those tips, and it's hard to tell for sure in your first post photos, but the centermost plants appear a little yellower than the lower leaves and those around the edges.