Deficiencies after flush

What was your reasoning for flushing?

What most people ignore about plants is that the halflife of chlorophy is two days. This means the plant is constantly producing new chlorophil for wich it need Nitrogen and other nutritions. If you flush your plant with plane water you take away all the nutriens for it to grow and/or synthesize chlorophyl. If you do want to flush, you always do it with half the concentration of your Nutriensolution and then you can implement a regular balanced feeding. I would always suggest to measure the runoff so you know exactly how much salt is in the soil. If it has good drainage, it should be okay to let it runoff a bit for mesuring. (EC or PPM) Your plant is pretty big so it needs nutriens for basically existing. You can‘t just pause nutrition. Thats all, good luck to you! 💪🏻🌱

Magnesium maybe lack, but after too much water i found correlation between magnesium and overwatering, maybe you suffocated roots ? In previuos week i see no issues, why you did flush in soil ??? Its for hydro or coco, not for soil technique. Lack of nitrogen comes too, but i honestly doubt that lack would come up so soon. More ph swing and lockout. Would not feed yet, light dose of calmag for few waterings if no return , then feed. But watch ph and let soil dry before watering again.