Brown patches on leaves overnight..

I’ve been battling with these seedlings like never before, had them in party cups in flood and drain for a month or so.. Been trying to combat magnesium deficiency for a while now too. They’re in coco btw.. Just when I thought I was on top of it these brown splotches appeared overnight and I’m so frikken bummed a lot of the new top growth has been affected.. any ideas on what it could be..? I’ve flushed and transplanted into bigger pots and given them a good top feed.. Any input would be so appreciated..

Looks like mag deficiency to me too

What's the RH & how's the airflow?

principlesarelife said:

What's the RH & how's the airflow?

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Rh is around 65 or so.. can get down into the low 50’s on occasion depending on the exhaust fan cycle which is on for 15mins every hour.. I did see it spike up into the 80’s though.. two small fans for circulation in this 3x3’ tent.. what are your thoughts..?

Been doing some more research and it looks like it might be Boron deficiency.. might be caused from some low Rh on occasion.. apparently it can be linked to cal/mag issues too..

This is what happens to your plants in coco if the coco dries out. It all has to do with CEC, cation exchange capacity. If the coco dries, the CEC lowers and your plants don't get all the nutes you're putting in.The same reason coco needs soaked in a high ppm calmag solution before using. The leaf twist with multiple deficiencies being shown is a dead give away. And the browning looks like it could be fungal, you may have two issues going here.