Leaf stem turning red/purple week 4 bubba kush auto

My temps don't drob below 17 Celsius at night. Day around 25. Humidity around 50

What temperature is your grow room? I was growing bubble kush and the stems went red when the temperature dropped too much at night

Food. She needs more food. Pale leaves, yellowing on lower leaves, and red stems. In this case I would increase the amount of nutrients. Red stems can also be caused by light stress, in which case you would only see it on stems exposed to direct light and not the ones in the shade. Genetics can also cause red stems. But based on the pictures of your plant, to me it looks like they need a higher nutrient level. Happy growing.

She lives in quite small fabric pot (1 gal) so it dries realtively quick. Every few days she gets around 0.5 l and I usually wait for the pot to get light. I've been going away for couple days and she got watered before she got dry as I was worried that she won't have enough till I come back. I have a ph meter and I adjust my ph with every watering. Last one was 6.5. I don't feed her heavily so I'm worried it may be some kind of deficiency. I'll run her with oh water and check runoff oh and ec after she'll get completely dry . Any other suggestions ? Thanks for help !

How much are you watering? The leaves look heavy with water, to me. Are you letting your medium dry out? Is your ph balanced? Do you have a ph buffer amended to your soil? As for the red stems, an excess of magnesium at a relatively high ph can do that, but I wouldnt be too worried. My photo bubba, dinamed, and criticals are all showing red stems, I'd attribute that to dinafems genetics.