Curling Up Leaves after Cal-Mag Treatment

Thats heavy nutrien burn Any calmag has nitrogen, yours are in overfeed and heavy, you just reached critical point, by ph i guess its soil. Would not recomend any flushes 0 feeding for 2 weeks, later return to pk part till flush or harvest. Light doses !!! Those leaves are dead, nothing will bring back. If you check run off, means you water with it, that prevents salt build ups - very good. But you overfed plants and long ago before ading calmag. I honestly fed with 2500 ppm and low ph, like 4.0 4.5 area, in 2 hours i had same look just rapid yellowing too. All equipment can go bad. Have always double to compare.

By the way, what was the ppm or EC of your last nutrient mix? Do you check? It is possible it's a hot nutrient mix, but if you gave all your plants a equal dose and only 1 is affected, then it's likely wind damage from the fan.

Looks like wind damage from your clip fan. It has to oscillate. You can't have constant wind directly on a plant it will get damaged from the wind. The humidity will get fucked up around the leaf tissue and burn them and force the leaf to retract to try to protect itself from damage caused by the wind. Mother nature never produces 24/7 wind.