If they`ve converted to LPA its overmisting. The choice is to carry on overmisting and increase the EC (just as you have) or stop overnisting and feed the normal HPA lower EC. The reason these issues crop up is the EC for hpa is geared to droplets that are instantly depleted of nutes on contact with the roots. When you overmist you lay down a film of water on the roots that sits for an age. Worse still, you now have a very weak liquid nute solution sitting on the roots, not contained in a droplet that increases in EC as its being rapidly absorbed by the root. The plant strips whats available from the water film but its not enough cos the EC wasnt geared for that delivery method.
The usual thing that happens is to decide the roots are way too wet and increase the pause time. The plants struggle more cos theyre having to wait even longer for what little is available. The correct solution is to decrease the mist pulse so the low ec can feed the roots in the way it should. Most HPA nute,ph, wilting ,yellowing etc etc issues are mist related. If you know how HPA works its not too difficult to diagnose.
