So I noticed my girls getting a few spots on a few of the middle and lower leaves. The spots are a rusty brownish color. After reading online I thought maybe I had mag deficiency. So went out and got some cal mag seemed to fix the problem for about a week but now it's getting worst. I tried to look around online for someone else with the problem before posting but couldn't find anything. I been checking for mites also and haven't found any. I'm about 3 weeks from harvest so not sure if I have time to fix the problem. But I would like to figure what's going on so It won't happen again. I know the pics ain't the best but only light source in my space is the grow light lol.
The yellowing at the leaf margins and the slight downward curling is common with Potassium deficiency. A flashlight or a household lamp on an extension cord would make for better pics.
Whats the environment like? its showing signs of high temps. and what about your ph? and the dead leaf looks like p deficincy
High temps would effect the upper portion of the plant the worst. That isn't the case here. That many weeks into flower I wouldn't worry about any deficiencies. You'll be flushing all nutrients out soon... you should see signs of deficiencies. It would be nice to know the problem for the future... but right now it's unfixable... too late. Give your last nutrient feeding and then switch to plain water for the final 2 weeks (you can add a tbsp or two of unsulphured molasses per gallon). What, how much and how often were you feeding? What ph do you mix the nutes to? What's the runoff ph?
I water them every two days. I always pre mixed my nuets in one gallon jugs. The ph in the water is always about 6.5 to 6.3. To be honest it's been a while since I checked my runoff ph. It was always 6.5 when I did check. I will check it today when I water again. I did check the soil ph it said it's at 7 . I'm not sure how accurate the meter is tho. What should my ph be on my water while flushing these last two weeks? Or does it even matter?