Mottled yellow leaves. What to do?

Help, my plant is turning yellow! Quckly fading… I think its a nutrient issue but have no experience troubleshooting.

6 wk old purple kush autoflower in soil. Plant is skimpy, mottled yellow leaves cropping up like crazy. Using Fox Farm nutrients. Ph 5.8 to 6.8.

It’s normal for a plant to shed its lower leaves at this point.

Strongly suggest not defoiliating so much on future grows. A plant needs its leaves to conduct photosynthesis and manufacture the sugars the plant needs to grow and be healthy.


Phof 5.8 is too low for soil. 6.3 to 6.8 is your window.


Soil or coco? The media in the pot looks like coco. As @Poseidon1 suggests, it matters for proper management of pH.


Are you a fellow grower or Forum facilitator?

Just one of the growers

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I checked this pH every time I water. Fox Farms says 5.8 to 6.8 range. Are you suggesting that I test the soil or the water going into the soil?

What are you using for a pH meter? A digital meter or a meter with prongs?

Test the runoff and adjust the input as necessary to maintain a runoff pH in the range 6.3 to 6.8. 6.5 is the sweet spot. Despite what Fox Farm says, 5.8 is too low. A pH below 6.3 can lock out phosphorous, calcium, and magnesium such that these specif nutrients are not available to the plant.

Do you have FF Coco Loco, or is it a soil like Happy Frog or Ocean Forest. It is important because coco and soil grows should be managed very differently from both a pH and a watering perspective… It looks like coco rather than soil.

Definitely does to me2.
@pollymex5000 , dont go out of the ph range to compensate either. If ph is low, do not go above 6.8 to correct, if high, do not go below 6.3 to compensate. Hope this helps

Also Ive never been a big fan of LST or much in the way of altering an Auto…I know some members do but I think most don’t…

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Unfortunately many new growers read that LST can improve yields and then extrapolate that more LST = more yield. The opposite is true. LST has its place, but overdoing it can significantly reduce yield.

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:face_with_raised_eyebrow: I have enough yield reducers IE:Caterpillars… Though this last batch Ive only found one so far…a few months ago (1st batch) I had more…last year was a bugger!!

Its a mixture of soil and coco. My first time using it and its different. More finicky. Probably won’t use it again.

It’s also doing weird stuff with my Krishna Kush plants the leaves are needle thin and twisted especially the new ones.

Update, i tested ph of runoff and it was low at 5.7%. But since I gave them nutrients this morning they’re looking even worse. See pictures. Yikes.

I moved the lights further away in case it’s stress? Things are going wrong and I’m thinking it’s the moisture control soil that I’m using, it has cocoa in it. Won’t be using that again but want a salvage what I have in it now. Also it’s providing opportunities to learn .Thank you Polly

Not a good idea to mix soil and coco as each is managed very differently from a pH and watering perspective.

Are you using a Miracle Grow or Vigoro soil? Moisture control is a no-go for cannabis as well, as cannabis needs wet/dry cycles.

I know. Wont be doing again but need ro finish thus batch first