Yellow and pale leaves of plants. Purple stems.

Those plants look stressed af. Why is your ppm so low? What is your RH and canopy temp? What’s is your light intensity(ppfd)

stems or petioles? thse are two different symptoms that point to 2 different issues. low P can lead to purple petioles. these are the 'stems' of leaves. low S can lead to red streaks in stems and may even turn completely reddish-purple as it advances. This can also be related to genetics. LED is also assumed to cause this. When i see it isolated at the top, i assume it's the lights. Right now i have this only at the top and even the petioles are 1/2 red on top but green where the light is shielded underneath. if you are in hydro/soilless it is useful to know individual ppm of each nute calculated from your guaranteed analysis lables. TDS pens measure EC and that is a guesstimate with a good amount of error. There are apps and web calculators you can use to do this.. just type in label info and it will tabulate it for you. assuming a roughly 1.3-1.5EC overall oncentration, you want Mg 50-75 range and S 100 and even a bit higher. YMMV due to your tap water too.. if it contributes X ppm of any of this stuff, you may need some small adjustments through observing and reacting to the plant. N 120-130s in vege, maybe drip 20ppm in bloom, but not much. P 60 K 180-200 Ca 100+ Mg 50-75-ish S 100+ this is a good ballpark to start in for hydro/soilless... always need a little trial and error to refine it, but this sort of formula will take a month or 2 before you see any visible symptoms and that tells you it's "close." The longer it takes for a deficiency or toxicity to build up the closer you are to feeding the plant on demand in a proper ratio. these problems only occur when rate of provisioningn does not match rate of use.. when you have a good formula it takes weeks or months to see an issue.. take notes, adjust, do better next time.. within 2-3 grows you'll rarely see any symptom outside of unavoidable and minimal senescence very late in flower. decimated canopies are not senescence.. that is user-error, to put things in perspective.

Are you soil or hydro? If hydro, You can drop easily half of your dosage to ~350ppm. Im Flowering week 4 and the girl eats under 400ppm. I keep 390ppm and it stays still. If you have EC meter start from lower dosage, if EC keeps dropping Then add more nutes, if it raises then go lower. If you are in soil, i think you should also drop some nutes down and check how girls react..

To be honest they look ok. If you are after a darker looking leaf you can defiantly feed your girls some nitrogen before you switch over to flower to darken them back up. Maybe a slight boost in iron as well will help color them up. If your intent was to switch to bloom fert, add 1/2 recommended bloom and 1/2 grow as your first bloom feed to get your extra nitrogen at the start of flower.

Revise su diario y esta todo en los parámetros adecuados. Los fertilizantes aplicados son los correctos. Tampoco se ven hojas de coloradas por falta de nitrógeno. Podría tener un verde un poco más intenso pero creo que va todo encaminado. Por el momento no hay de que preocuparse. Saludos.