- Aug 20, 2018
I too have had this issue but not as severe as you. As I understand MC2 the small little "rocks" contain the Calcium so every time I mix up my nutes I am sure to have enough of them in it. It did not stop it but it kept the spots to a minimum. I harvest 4 of them yesterday.Im not expert by any means but I will have to disagree with some of what has been said. Its definitely a Calcium or a Magnesium deficiency. But which one? Im going to lean towards calcium where it seems most are leaning towards magnesium. For the simple fact, going off your pictures, it is spotting near the top and newer growth. Magnesium deficiency spots are almost identical but it tends to effect the middle and lower growth first. You do have the yellowing that tends to come with Mag deficiency, but you also mentioned some possible bleaching issues being caused by the lights.
With that being said ... Id start with making sure your PH is optimal for calcium intake. Also give them a good dose of supplemental (75%) and it should stop it from getting worse after a few days. What is damaged is done though and will not come back. Good luck! PS. I ran into this exact same issue last run with MC2.0 towards weeks 7-8.
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