Is the browning caused by nutrient burn or symptom...

It's definitely needing a boost of pk, that will heal the purple stems. The slight yellowing in your leaves can be a calcium magnesium defeciency which you can easily sort by adding to your feed some calmag. 🌱👍Buds are looking sweet though

Hi Elevatedthinking This should help. I believe what you have is a phosphorus deficiency. When plants lack phosphorus, purpling or reddening of the leaves and stems can occur. Signs usually begin in lower leaves and branches and slowly work their way up the plant. Bear in mind that some plants naturally turn red or purple due to their genetics but if you keep having this problem with many different strains, it’s probably not due to genes. Overwatering and cold temperatures can also exacerbate the problem so make sure those aren’t an issue for you before trying to add more nutes. Phosphorus is the “P” in NPK (Nitrogen, Phosphorus, Potassium) meaning it’s a major nutrient needed by the plant to thrive. Most fertilizers made for the flowering stage will contain plenty of P and sometimes growers will mistake a pH imbalance for a deficiency, although it sounds like you check pH often so in your case I think it’s truly a lack of Phosphorus. In order to treat this deficiency, you need to add nutrients with phosphorus. Organic forms of these include worm castings, bat guano, bone and blood meal and crab shells among others. If using bottled solution, use something where the NPK shows high levels of P. Most flowering or blooming nutrients meant for cannabis contain plenty of P. You should see the problem clear up within a week or so with new growth looking lush and green. I am using 6PH for soil growth and never got PH in balance. Good luck hope this helps.

this could have been later in the final phase.Yours had some little nutrient burn and you flushed,now it is showing hunger signs.Give maybe a PK booster along with your base bloom nutrients.runoff 900ppm is really good,clean soil.That plant with browning must be a sensitive one when it comes to feeding.Just keep feeding,no need to increase dosage,keep the soil clean like this and it'll do no harm to your plant.Everything looks fine.But leaves looking pale to me on the other one.It needs more feeding.