I have absolutely NO idea how the idea of Ca deficiency came into play here! :wtf:

Purple petioles and stems are signs of Sulfur deficiency, low temps, or even simply related to the strain.

You need a better fertilizer either way. The MG you are using isn't appropriate for any cannabis life stage, and your dosage rates are no good anyway.

You also need to check the pH of your soil runoff to eliminate lockout.

Without a better pic that shows more of the plant, plus info on your growing conditions (look in the sticky!!!) all this is just guessing.
stinkyattic Reviewed by stinkyattic on . Stems and Stalk Are Turning Purple, Help! Pics Included I've noticed that the stems of my plant are turning purple, also the stalk has some purple showing as well. Does anyone know why this might be? I am using 24-8-16 Miracle Grow every few weeks. I have two 40 watt fluoros that are kept on 24x7. Any replies will be appreciated. Thank you. Rating: 5