Im starting a room here in michigan. I have nine different strands between my 24 plants. I have them under a 1000w HPS, in 5 gallon smart pots, temp 74 humidity 45%, but in four of the strands I am seeing leaf curl. I am quite positive that it is not bugs, nor disease, which leaves my with nutrient burn. My ph is 6.5, and the plants are near six inches.
My first round of feeding I went roughly 80% dose as per instructions and saw nute burn in four of my strands(1300ppm). I flushed for a week and once they looked healthy again I fed, but this time with 50-60% dose(900ppm) and I am still seeing nutrient burn. I can state that one of the four is in soil and being fed coco, but all other sit in a coco medium. Any advice? After I post this I will attempt to take some photos