(HELP) Yellowing On Upper Leaves On Auto

DaddiiDiiDii

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Ok my friends as the title says I am having some yellowing on the upper leaves of this AK-47 Auto. She is currently almost at the end of week six since sprouting and has been fed on all Biobizz products. The medium is All-Mix and I am using Biobizz grow at 1ml per liter, bloom is now at 3ml per liter as the chart suggests for her age and I started her off in plant magic old timers granules and biobizz root juice just for the first feeding.

12L fabric pot with LST but more recently defoliating as I had no choice because she was so bushy that mold was almost guaranteed. The tent is a 120x60x150cm and my light is a Mars Hydro TS1000 currently at 20" from her top which I started around 70% dim and raised it to 100% as she went into flower and the temps have been pretty stable around 25c and humidty has been in the ranges of 65% to 70% and my light cycle is 24 hours. Just before this happened I added in two blurple LED lights called 'Likesuns' which are rated at 600W but I have taken them out as I suspected I was overdoing it it with all the light since there are only two other AK autos in there who are almost four weeks old. This one is 15" in height.
I haven't been PHing my tap water as my meter is broken but also I have read that when using all organic medium and nutrients there is no need and I have been feeding only when the top soil is dry which is about every two days.

Apart from a little bit of nute burn on the edges of some leaves there hasn't been a single issue and she has been growing leaves faster than I can defoliate. I have the bottom two air vents open on the tent and a fan extracting the air at the top and I open the tent a few times a day to spend time with them and make sure fresh air is indeed getting in.
I have checked the leaf chart to see what it could be but it could be one of a few things and so I figured I would let the experts here take a look.

Yellow (4).jpg


Yellow (3).jpg


Yellow (2).jpg


Yellow (1).jpg


As you can see by this last pic the lower leaves are just fine so it is definately starting on the new growth at the top. I have just given her 1ml of Botanicare Cal-Mag Plus as after doing some digging online that seemed to be mentioned quite a lot. Any help would be greatly appreciated and thanks in advance.
 

WeedHopper

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Yeah I can't remember on the old verses new but I know the new growth will show you if your feeding correctly are not. If the PH is correct,,the new leaves should be green.
 

pute

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Looks like a nitrogen deficiency to me. You either starving them or they are suffering from lockout. Like indicated before from Hopper and fogey it could be a result of pH.
 

DaddiiDiiDii

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I checked about nitrogen first and it starts at the bottom and this is well and truly starting at the top and not affecting the bottom leaves at all. Like I say ph shouldn't be anything to do with it since it is all organic and from what I gather organic medium and nutes regulate the ph themselves unless of course that is complete misinformation I have been reading. After having alook at the link oldfogey8 posted I think it absolutely is light burn and I remember now long before this started the upper leaves did start curling upwards but I figured since it didn't seem to get any worse that was just how that strain was. I guess I should have listened to what she was trying to tell me early on.

Thanks for the advice guys, appreciated.
 

oldfogey8

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He also said right before it happened, he had added 2 ‘600’ LEDs. They plants may have needed to be ‘hardened off’ to the added intensity(like when taking plants outside into the sun).

A lot of people have been having problems with municipal water lately having pH fluctuations. Or this plant could just have different nute requirements than the shorter plants and it may need a higher dose of the Biobizz grow(maybe 2 ml per gallon instead of 1 ml/ gallon).
 

oldfogey8

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I checked about nitrogen first and it starts at the bottom and this is well and truly starting at the top and not affecting the bottom leaves at all. Like I say ph shouldn't be anything to do with it since it is all organic and from what I gather organic medium and nutes regulate the ph themselves unless of course that is complete misinformation I have been reading. After having alook at the link oldfogey8 posted I think it absolutely is light burn and I remember now long before this started the upper leaves did start curling upwards but I figured since it didn't seem to get any worse that was just how that strain was. I guess I should have listened to what she was trying to tell me early on.

Thanks for the advice guys, appreciated.
Organic growing generally does not require pH’ing. I have used organic nutes and soil for years and have not checked pH in years. However, as I said in my previous reply, people on here have been seeing pH as high as 10 in their tap water recently. That will screw up even organic grows.

That growth if light burnt, will not recover but the plant will. If you want to add new lights, it is a good idea to do it gradually. If you are not familiar with hardening off plants, you just introduce the plants over a week or 2 to the sun. Maybe use one of the new LED’s at first all the way at the top of the tent and lower it down gradually over a week or so. The TS1000 looks like it is designed for a 2x2 ft space so more light in your 4x2 ft tent would be helpful.
 

DaddiiDiiDii

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I'll deffo get another ph meter just to be sure and it's always good to have one anyway. I do think I blasted it with sticking those two other lights in like I did like a plank but you live and learn. At least I will have more of an idea what the younger ones will need now as well.
 

Oldbay

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Agree with the above but I’d get some Epsom salts in the water for the next few feedings to help out. 1 tbls per gallon
 

Carty

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Feed that sucka.... she's craving foods, and looks like mostly blooming ferts like P & K she wants..
also, you running any micro nutrients.. molybnium or however it's spelled does this too.. and since it's all the way thru the plant to bottom leafs, it is NOT light burn at all.. no, I'd flush her, then start off feeding her half strength with a bloom booster if you have one. also, she should be getting 1/2tsp calmag weekly.

be careful, don't panic.. it's just a tweeking and she'll come back just fine.. but I always start with a flush until water clears up.. then feed so I know what is in the medium for the plant...

luck
 

MechaniMan

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I'm not the most experienced but that looks a lot like what my plants do sometimes and I usually correct it with CalMag. When I give them CalMag it usually tends to resolve within a couple days. One thing's for sure giving them CalMag won't hurt.
 

RosterMan

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Did you manage to figure out what was wrong? I can tell you that I've been struggling with yellow leaves for a while, and for some reason, nothing could help me. Maybe it was just because I didn't have green fingers, and that's why I decided to turn to DELETED and start ordering cannabis instead, now I don't have to worry about anything like that.
Nice try
 
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