Indeed, it's sort of like flying blind. What would you think about this idea: completely flush the soil and add solution of GH + calmag at 1.6 - 1.8EC (800 - 900 ppm). Obviously I can't actually measure it so I'm going by the EC values interval on the bottles.It is possible that you have a lockout if you d been feeding that much. Without numbers you’re just guessing.
Ton kind of reset the situation. I did raise the light too.