72 right now and cloudy. when i started these they were in temps as low as 30 but now its finally picked up but never has been over 80 this summer yet (new england). and someone said the purple may be phosphorus but only 1 of my plants is doing that and i'm pretty sure there both females(?).
they look good man, keep us posted on the budding, have you seen pre-flowers yet? im growing in new england too near boston, but only started getting some pre-flowers today.
pre-flowers is just the beginning of flowering where the pistils emerge from some nodes. once pistils are emerging all over and you start to see defined buds beginning to emerge you should switch to bloom foods
something like fox-farm big bloom or even some sort of dry crystal 'bloom food' from the grocer would be fine. bloom has a characteristically higher p and k than n. careful not to over feed it
i dont think their turning purple, that looks like strecthing on the leaves. if it was purple, leaves and buds turn purple, never seen a straight purple stem in my life, and ive smoked alot of purps