Red branch?

Soil: Mg potting mix

Water: tap water thats sat out for 2 days, PhD at 6.5

Lights: 4 100W 2700k CFLs (Just made my flower room and put her in there last night, She used to be on 1 40W flours, and 1 60W 6300k CFL)

Im not giving her any food because of the time release ferts.

She has 3 branches that are reddish.

She has no other problems.

Any pot gurus out there know whats going on?

could be a phosphorus deficiency, how old is the plant?

Shes about 6 weeks old, and a foot tall.

same issue with my girl, except shes almost 5wk into flower. i added some ferts two days ago. ill post before and after pics in a day or two showing any changes.