Yellow Spots and Leaves Curling Up - Magnsium?

I am having a problem on a couple of my plants. I missed a couple when hand watering ( soil ) now the leaves toward the top of the plant ( old and new foliage ) .
The leaves are curling up, could this be mag def? 4 weeks into flower.

I only have this pic of the leaf. I want to get in there tomorrow when the lights are off and snap some of the plant. I will post update.

Any advice would be appreciated

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Manganese deficiency?

You should probably post your grow specs to help.

Check out these threads, they are pretty informative:

[h=3]Guide to Nutrient Deficiency or Toxicity[/h]
[h=3]Guide for Diagnosing Plant Problems[/h]