Any updates on the results? After squaring my Veg room away (brand new room, first time grower) with its environment issues (heat) all the new growth looks really really good. Was it Cal or Mag in your case? You're plants looked a lot like mine did so I thought with the change in outdoor climate (summer's here) it might be that
Good Luck!
Yeah, the results are they were in a newly constructed vegging area which initially had no fan and no humidifier.
Even thought they were under T5 lighting it was getting hot and there was also low humidity in their.
The soil is/was very rich with added organics.
So I bought a fan and a humidifier for that area, so that alleviated the heat stress.
I also just watered with just water for that period since the soil was so rich, so that elevated the pos nute burn.
I started watering less and administered some mag, after which the problem ceased.