Hi guys I’m in flowering stage with my clones an...

Remove all damages sickly looking stuff to not get sick and spred something

And red stems is potasium the plant needs a lot of that I would flush to eliminate nutrient lock up or PH issue then feed with a week 6 flower scheadual feed

I would almost say Norman nitrogen loss from flowering is normal but you have sulfur deficiency

https://www.dudegrows.com/cannabis-deficiencies/

Hi wakesk8. It looks like your in around week 6 if flower? Leaves starting to yellow later in flower is normal. It's called senescence. But I don't think that's what's going on. The leaves burning from the tip back toward the stem could be due to a few things. If you are providing way too much calcium, that could happen because it can block other nutes. If you're not providing enough potassium, it could cause it because potassium helps to regulate the plant's inner temperature. If you are over feeding it could cause nute burn. If you are over watering it could block nutes. If you aren't providing enough magnesium, other nutrients could be blocked; both N and P are synergistic with magnesium. The more N or P you provide, the more magnesium you need to also provide. Otherwise, it could also be caused by a pH imbalance which can also block other nutes and maybe cause a toxicity of one while also looking like a deficiency in another. Can you elaborate on what you are giving, what quantities, and how often, as well as a description of your water; is it tap or RO or bottled, or...?

Hi, That looks a little like Potassium deficiency. Cal-Mag looks more like rust spots. But you might be right, you might have PH issues that are causing a nutrient block, and it might not be uptaking Cal-Mag. Have you checked your runoff? If anything is off, then do a small flush until you get a consistent PH and then check TDS/PPM and make sure you're not over-fertilizing the soil. I also can't really tell the medium, but if your using soil, then you will have fewer Cal-Mag issues, but this is an issue more for Coco growers & hydro. Hope this helps, nothing worst than having issues at flowering