Mother plant not doing so well...? Help! PICS

Mother plant about 6 months old, grape ape strain. Fox Farm Soil, Fox Farm grow big nutrients every other feed (700 ppm, 6.8 ph). Water is 120 ppm from tap.
Looks like cal mag def to me, but unsure..? Since tap ppm is only 120 I am thinking maybe not enough? I'm afraid to add cal mag to the mix in case she's getting too much, or is she not getting enough, she's getting plenty of nitrogen, this isn't the problem... Help! The spotted leafs are spreading like aids in africa! If you don't know what your talking about don't reply (tired of noobs guessing and telling me bs they read from jorge cervatnes book)
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Add some dolomite lime. 6 months in with FFOF, what was in there is depleted. FFOF uses oyster shell flour (Ca only), so you're probably light on Mg too. A tsp of epsom salts will take care of that. Dissolve in water or top dress with it, your call.

If not dolomite, calcitic lime is goo too. Add 2tbl/gallon of mix. Top dress and regular waterings will take care of it. Available at HD or Lowes. $4 for the dolomite, ~$15 for the calcitic. Both are 40lb bags.

Wet

How big a pot is it in?

Looks like some mag will help it in my opinion.