What kind of deficiency is this

[darkgrower]

My plants started having yellow tips on their top leaves, new growth, I am wondering what would this be? They are in their 7th week since seed (3rd week of flower).
Could it be CalMag deficiency or nutrient burn or something completely else? I lifted the lights and they are around 50cm from the canopy now.
View attachment 1772312View attachment 1772313

 

[DreamingHigh]

Looks like nutrient burn. You might have found your max feed strength

 

[BII]

Now you need to decide to continue to feed the same, pushing the limit, or be more conservative and cut back. I'd cut back just a little.

But if not already, you should be switching to bloom base nutrients. So you'll essentially have to start over with new nutes that may act differently.