Potassium deficiency or nute burn? HELP needed

[Kush420]

Hi everyone,

First time growing Auto's and this issue is puzzling me a little bit... so here for some advice

I am using BioBizz nutrients line: Grow, Bloom and Topmax, also add a small amount of Calmag Extra each feed too. Plant is in Week 6 from seed and soil pH is 6.55/6.56 at run off. Introduced topmax on Monday. My feed is usually Monday, Wednesday, Friday with a few small dry days in between to prevent over watering the soil.

Does the leaves here look like a Potassium Deficiency or something else? I made a light flush yesterday and the run off pH was coming in at 6.55 to 6.56 with a ppm of 376 at the run off so I dont think its a nutrient lock out?

RH between 55% and 65% - light is at 19 inches from Canopy at 116W, half power QB, which is a 240W board.

Temps from 27 to 30C





More pics from today:



I can post more pics but the issue seems to be effecting the 2nd, 3rd and 4th set of Fan leaves from the top of the plant on one of my auto's. The strain is Malana Bomb by Barney's Farm.

Also if anyone is using BioBizz could you tell me what your Schedule is for Weeks 6 to end please?

 

[Kush420]

Any help appreciated. Symptoms appear to be worse today. Got a higher PPM on a new feed of 596 ppms

 

[Mr Green Fingers]

What are your temps, Rh and how close are your lights?
Looks like it could be heat stress with the serated edges curling up but I am far from an expert but the gurus here will need that info for a diagnosis.

 

[MesaBoogie]

What are your temps, Rh and how close are your lights?
Looks like it could be heat stress with the serated edges curling up but I am far from an expert but the gurus here will need that info for a diagnosis.

I'm no guru either, but I agree there is definitely some heat stress or light stress in play with those curled up edges. I think that's a good place for you to start for the moment. Backing off the light may stop what ever else we are seeing.

 

[Kush420]

I'm no guru either, but I agree there is definitely some heat stress or light stress in play with those curled up edges. I think that's a good place for you to start for the moment. Backing off the light may stop what ever else we are seeing.

Light is a 240W QB @ 116W at the wall, so just under 50% power at a light to canopy distance of 19 inches.

 

[Kush420]

What are your temps, Rh and how close are your lights?
Looks like it could be heat stress with the serated edges curling up but I am far from an expert but the gurus here will need that info for a diagnosis.

Temps range from 27/30C, RH between 55% and 65%, Light is running at 116W power and 19 inches from Canopy?

 

[MesaBoogie]

Sadly I don't have any experience with QB's , but I'm thinking 19" is to close for this girl right now. Any time I see my leaves curl at the edges like that I back my light off.

 

[Kush420]

Sadly I don't have any experience with QB's , but I'm thinking 19" is to close for this girl right now. Any time I see my leaves curl at the edges like that I back my light off.

She's in Week 6 of grow from seed and flowering already? 18 inches is a safe point for QBs... Other people i've spoke to said Potassium deficiency, the browning is what is of concern, the curling is a bit of an older issue.

Appreciate the reply though

 

[Kush420]

Update: Moved my QB to 21 inches but the heat stress was a few weeks ago, the issue in the post is related specifically to the leaf serrations browning but i am grateful for all input.

Thanks.

 

[MesaBoogie]

hopefully one of the ol timers will be around to give ya a better diagnosis. Some pretty smart folks around here. But in my experience any one of too much light, too much water, too much nutrients leads to all the ugly stuff. So I think you moving back the light is a good place to start as it's obvious it's a contributor.

What kind of soil are you in ? Whats the PH of your water ?