Lol @ xmobotx
I don't think purple stems are a deficiency, mine all have em, but it can get a bit chilly in my room..I think it's just that.
i would just about bet some of that is strain dependant
i get 'em in a consistently ~70-ish or better environ but i also micro amend so; i need to run some a little hotter-mixed {nut-wise} and see how they respond to more foodz
i have a funny feeling this stuff might just have red stems