Sad Photo

never got high off 6 grows and plants were looking very fine but way too much nitrogen. not making that mistake this time. leaves were the same dark green as you have so over fed would be a guess. is your ph pen true? was another prob i had. gl

Waaaaaaaaaaaaaaaaaay over fed and not being kept moist and/or not getting 10-20% run off each time you irrigate, causing a nutrient build up in the coco, causing a toxic situation. Coco pH around 5.8 to 6.0 is recommended.

Looks like you are not providing enough run off. Coco is always suppose to be wet. You have a salt build up. You need to flush the coco till the run off ph is about a 5.8. You have toxicity from build up. Coco is nothing like growing in soil.

pH is too low raise it to 6.3

Looks like it’s way overfed on nitrogen which is causing some sorta block on potassium and probably other things