Red stems cracking down the middle, lines down the stalk, leaf veins turning red.

Red stems are just from the LED and sometimes genetics . Plant looks healthy .

She is hungry. Give her good nutri's for flowering with miroelements complex. Once she started flowering, her needs are different than 1 week ago. P + K + microelements should give her a boost that needs. Maybe ur slightly overwatering her, seems like for me. Lower water doses, feed and wait. 3-4 days of proper treat and will recover fast

Hello my friend! You got everything under control but you need to start feeding the plant. You can start using a basic nutrient for the flowering phase and start with 500 ppm. The red stems are a sign from stress. But next to those red stems your plant is looking healthy.

0.4 EC I think you are underfeeding them. Mg and S and P come to mind with red stems. Look at your feeds and confirm what the concentrations are and ensure they are getting adequate levels of both micro and macro nutrients. Can check out other grows with that strain to see if any of the other ones turned red/purple to get a better understanding if it could be genetics. Good Luck!

Those are just the genetics brother. Your plants look great! Don't worry about purple stems unless your plant becomes weak and can't hold itself up. Hope this helps

Looks like it was stress induced. Add a pinch of epsom salts next couple of feedings. Also up the bloom nutrients from now on.

Your plant is under-fertilised: the red stems indicate phosphorus deficiency and the red lines on the trunk indicate widespread deficiency.

This can be genetic but has symptoms of a possible S-deficiency. Is the apical meristem "woody" at the bottom? that is also a symptom. i've had plants do this then the streaks continued to progress to a full red /purple color, but was giving 100ppm of S which is plenty. This can happen by itself. color in petioles is no realted to sulfur. This could be a p-deficiency, but more likely LED/genetics related. i've seen people try to blast it with 100ppm of P and doesn't have any effect on the purple petioles. P above 60ppm doesn't correalte to any measurable benefit for vast majority plants. wouldn't rule out an oddball, but oddballs are just a reflection of a poor breeding selection. so if you are soil and don't fertilize every irrigation, probably need roughly proportionally more relative to fertigation frequency difference... prolly a bit less as soil is slower growth rate and needs fewer building blocks per time increment, in general. Cant tell if it is light related in pictures-- is there some paleness creeping in (starting at tips) to lower leaves? if so, may need a slight boost to N. plants look realtively healthy, i'd lean toward genetics here. double check how much S you provide over time. The numbers i give are for hydro/soilless context, but over time have to add up to similar masses per week or month relative to growth rate, regardless of medium used. These are building blocks along with carbon and new plant mass do not spontaneously manifest.