You have serious ph problems. Then you hit with flush what was the ph of the flush if your plant was in low 5's and you hit it with 7.0. You shocked them and the ph problem has caused a nutrient lock out that caused a nitrogen run away. Now your nitrogen Toxic. Also it's compounded by not enough light as is to stretched out. Never use both ph up and down in the same batch of water if you miss the ph with down then start over.