he he, so you learned that red stems and petioles arent always a sign of potassium or phosphorous deficiencies. You have arrived. Strain related as you suspect.
I wouldnt take my word as gospel and should always take the measures to assure your nor dealing with a defish. But some strains do have that trait in the gene pool.
Black indica chopin down today. 7 weeks. 1 week flush. Just makin room under the light. She had problems in the begining . So shes skinnier. Doesnt pack on weight like the others. Shea real sweet smellin tho. Maybe diffr pheno. Hope all is well.
Remer a year late I am, I have some Humboldt Black indica in my grow this year. Finding it hard to find pics or info on it, appreciate if you know more. Yours not so black but looks good! Nice pics...DD