Does she has phosphorus deficiency or this is anot...

Hey there so I'll agree there's definitely signs of magnesium but youve been adding in calmag for the last couple weeks and it looks like it gets a little worse each week. Perhaps the magnesium is present but no able to be taken in either by too much calcium which can lock it out, having your ph below 6 can make it a little less available and also to high potassium can block it out as well. Id say either flush out the system and rewater with the nutrients at 6 and see if it can take in the various nutrients better otherwise id get epsom salt which is just magnesium sulfate and possibly foliar it or just water in...but the roots will definitely have better access to it at the 6ph vs 5.6 and watch for some changes. It may be the slight ph change makes all of your feeding a bit more available. Good luck with ruling everything out. Happy growing ✌️