What are these lines on my branches

[Zmart]

Black or very dark red lines going up my stocks any idea what this is?

 

[Bigalmoby]

I would say it’s the strain with the little info you gave

 

[ArtfulCodger]

Could be the strain. Could be a stress reaction to too much light or a nutrient issue.

 

[Zmart]

This is bread and butter by exoticgenetix. No change in light or nutes. They’re under a 315 comb and a 150 led getting watered at 6p.h. Every two days with general hydroponics flora series every other watering. I did just add some steaks to help hold the buds. Could this possibly be stress from root damage?

 

[Phyto]

Many plants get red stripes on the stems, it's notmally genetic, if you're not having any other issues, I wouldn't be concerned.

 

[Fnipernackle]

Black or very dark red lines going up my stocks any idea what this is?

It's fine. At worst, it's very minor stress from any number of sources. It could also just be genetic. Unless you start seeing symptoms in leaves, don't worry about it.