Praying for Mg is a myth. Mg def presents as a regular striping between veins.
Looks like you've got potassium locked out somehow.
I'd go back to the basics, foliar feed with a weak solution of the GH micro to keep it from getting worse, lay off the Epsom salts, be certain that you've got calmag or that your tap water is providing sufficient micros, monitor pH carefully... you know the drill.
All this multiple-nute hydro chatter makes my small brain hurt.
Honestly I'd lay off the liquid karma and sweet until you know what's going on. But that's my personal opinion.

In my own hydro dabblings and splashings, I go by the 'less is more' approach to supplements- I use half as much as the rec. dose, and only topmax and molasses. I figure, a living plant that survives to harvest yields more by definition than one I've killed with supplement overdose... Weedhound may remember my misadventures with 'gravity' this summer... hahahaha what a fucking MESS.