Yet another question about yellow leaves

Hi, just looking for some opinions on my yellow leaves.

I’m in a 4X4 tent. 550 watt LED. 6 5-gallon pots. I use So-Hum Living Soil with a little bit of Nature’s Living Soil mixed into the bottom couple of inches. I use the Blumat watering system. There are 3 Bruce Banner and 3 Grand Daddy Purple’s. These are feminized autoflowers grown from seeds from After about 3 weeks I started treating every few days with Dr. Root from Cultured Biologix, and then stopped about 4 weeks ago when flowering really kicked in.

These girls are 9 weeks old, so I think I have 3 - 6 more weeks before harvest. The light at this point is about 2.5 feet above the tops. Can’t get it any higher in the tent.

So the girls are really starting to yellow. it’s been happening slowly but seems to have accelerated in the last week.

My guess is heat, light burn and PH. I finally got a PH meter and found my water at 5.5. So I have corrected that to 6.5. The temperature is 77.5 and the humidity is 54%.

Until the yellowing started, these plants were strong and had deep green leaves. Really looked good. The buds are looking pretty good. I just don’t know if I should treat for some other problem (maybe throw in some calcium and magnesium?) or just ride it out.

Any thoughts?

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So fan leaves yellowing off and dying is normal in late flower which your plants look like theyre in.
I will say though from the looks of the leaves your plants were probably a bit hungry for Phosphorus/potassium. For typical yellowing of fan leaves in late flower it usually starts from the bottom up as you lower the Nitrogen. Since your newer growth is yellowing out first (higher leaves) its prob something a little less mobile or abundant.
At this point I wouldnt worry about it too much other than to make sure to remove any dead/dying leaves from near your actual buds as possible. If it looks like its yellowing and dying off, remove it. You could probably prune out alot of veg growth in the bottoms too to increase airflow for late flower.
keep watering and feeding and maybe up the P but def the K towards the end of cycle before a flush if you do one.
dead, dying plant material is a welcome mat for fungal pathogens, keep airflow up and make sure to clean out the dead stuff
good luck dude!


Just a quick update. Other than fixing my PH problem, I decided to wait a few days. So far they are looking much better. I’m still losing leaves but overall the color is coming back and it looks like they are naturally heading into fall. Hopefully this keeps up for another 3 - 4 weeks to get me to harvest!

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