Is this a Magnesium deficiency?

[IhatePM]

middle of week 5 of flower and one of my dolato has major red stemage. Is this normal, or should I up the mag?

 

[KDB42]

From what I know that could either be stress or it could be a trait of the plant. My guess would be stress from heat (in my limited experience) but just guessing.

 

[IhatePM]

it is toasty is there