Critical Mass / HLG 225 Elite v2 / 2x2.5

Seems like Nitrogen Toxicity. If you are growing in Coco you need to have runoff, measure the runoff, and keep the numbers balanced. If your inflow, as you say, is at 350ppm, you need to make sure your outflow is somewhere around there, if its less then you need to increase feed or increase the times that you are watering aday. If its more then you need to lower your feed. You ALWAYS need runoff, washing off the previous feed and providing a fresh new one, daily. NEVER follow a wet/dry cycle as it is not soil. You probably stressed the plant during transplant by washing off the roots etc, this looks like a few things, my first guess is N toxicity, but could also be Mag deficiency. Also another thing to note is that if you used tap water to flush the rootzone you most likely killed all the colonies established from the voodoo juice with chlorine... If you are using Mycorrhizae, fill a container with water and let the chlorine evaporate overnight. I use bottled water from the supermarket :) Hope this helped :)