Is this nutes burn or light stress????

A

adam2706

Active Member
I have this plant (purple kush) showing signs of stress. My other plants (lemon pound cake) aren't showing any major issues and are on the same feeding schedule and nutes. I'm assuming this is nute burn or light stress. It appears it is only happening on the more mature leaves, new growth looks good.

I run rockwool with drippers and just dropped the ppm from 1100 down to 830 yesterday for fear of nute burn.

Week 4 flower. 81 deg/48% humidity. Lights are 18" above canopy. Nutes PH is 5.8

I'm heading out of town tomorrow and have to make the adjustments asap. Also, do I remove the effected leaves, or leave them on?

TIA
 

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calvin.m16

calvin.m16

Well-Known Member
adam2706 said:
I have this plant (purple kush) showing signs of stress. My other plants (lemon pound cake) aren't showing any major issues and are on the same feeding schedule and nutes. I'm assuming this is nute burn or light stress. It appears it is only happening on the more mature leaves, new growth looks good.

I run rockwool with drippers and just dropped the ppm from 1100 down to 830 yesterday for fear of nute burn.

Week 4 flower. 81 deg/48% humidity. Lights are 18" above canopy. Nutes PH is 5.8

I'm heading out of town tomorrow and have to make the adjustments asap. Also, do I remove the effected leaves, or leave them on?

TIA
Click to expand...
That is definitely burn, not deficiency. Temps are warm, humidity is dry, this equates to a high VPD meaning transpiration is happening fast, Uptake is happening fast. In this scenario you will want to use a lighter feed strength. Probably even lighter than 830 "PPM". Do you know if your meter is reading PPM on the 500 or 700 scale? I have switched to using EC to avoid confusion. The only time I'mf eeding plants 2.0 EC (1,000 PPM TDS or x500) is when they're in very large pots and I'm watering every other day or once a day at most. In rockwool with drip feed I'd run literally half that strength, around 500-600 PPM or 1.0-1.2 EC.
 
A

adam2706

Active Member
calvin.m16 said:
That is definitely burn, not deficiency. Temps are warm, humidity is dry, this equates to a high VPD meaning transpiration is happening fast, Uptake is happening fast. In this scenario you will want to use a lighter feed strength. Probably even lighter than 830 "PPM". Do you know if your meter is reading PPM on the 500 or 700 scale? I have switched to using EC to avoid confusion. The only time I'mf eeding plants 2.0 EC (1,000 PPM TDS or x500) is when they're in very large pots and I'm watering every other day or once a day at most. In rockwool with drip feed I'd run literally half that strength, around 500-600 PPM or 1.0-1.2 EC.
Click to expand...
Sweet, thanks. That is what I was assuming. I have been flushing with just RO for about a day to try and rid the RW of any buildup. Today I will mix up a new batch of much weaker nutes before I head out of town. I am on the 500 scale. Fingers crossed they recover.
 
Hiphophippo

Hiphophippo

Well-Known Member
I’d say more fan wind burn doesn’t really look like nute burn are your fans heavy or where heavy in that area with some dry back and a a lot of wind you can get that. I would check air movement there and adjust accordingly wind high light and some drying will do that.
 
Hiphophippo

Hiphophippo

Well-Known Member
Nice with the underneath light that’s how I do it. Do you run your light through veg or just flower
 
hotrodharley

hotrodharley

Well-Known Member
I’ve got to agree with the idiot above on potassium deficiency. Assuming lockout because of the high EC.
 
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