Mid grade, purple stem

Me and a buddy of mine who are both doing seperate grows, using the same mid grade seeds (i also have online seeds), got purple stems on all the mids. The plants in each grow are very health and arn't in the same growing conditions, ive heard purple stems is a deficiency but i think its unlikely we both have this same deficiency on about 20 plants using completely different things. Could this just be the genetics? This is from the best mid thats ever come around, huge dense nugs with patches of purple all throughout the buds, crystals, very stanky. The seeds that came from this weed were very walnut like seeds fully developed and all germinated in 1-2 days. The plants grow with very tightly space branches and have a good smell as soon as one week old. Any info and advice would be appreciated, no haters please im jus really high, sick and tryin to get some info.

You're fine. My strain always has a purple stem about 3/4 from the top to the bottom, then turns into the typical branch after that. No def for sure, the strain has been this way for years.