New Leaf tips turning grey and curling!? with Photos! PLEASE HELP!!!

Howdy y'all!
I have just noticed that the leaves at the very top of my vanilla kush have started turning grey and curling up.
It is just over 4 weeks into veg, and I have LST'd it.
I'm using biobizz lightmix, and at the last feed used 2ml per liter of bioGrow, PH'd at somewhere between 6 and 7 (nearer to 6 though... I use pH paper so can't be any more accurate)

I have looked through the plant diagnosis threads, but could not narrow it down.
Could simply be thirsty? Or could be overwatering. So I don't want to exacerbate things!
I don't think its nute burn as it only affects the top, newest leaves.
And I don't think its heat stress either, as they have not gone crispy at all. The grey curled bits feel quite soft...
Does anyone have any ideas as to what could be causing this? And of course, how to fix it before its too late!?

Many thanks folks!
Photos below...

Woah, we are in the same situation. I'm having the same problem on one of my plants. I can guarentee it's not heat stress, and it's only happening to one out of my 6 plants.

The problem is a micro nutrient deficiency. It looks like Zinc is being locked out. Zinc can be absorbed by the plant with 5-7 ph. I suspect your paper strip is indicating a higher ph, as this type of deficiency simply does not show up if you are using a complete fertilizer system. You can add a galvanized nail to the soil, but that can take a while. Any nutrient that has potassium in it will solve the problem quicker, however I caution, this deficiency is rare, and I suspect your PH is too high or too low. A meter would be an excellent investment.

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Not to hijack this thread or nothing, cause his may be due to PH. I went and tested the ph and it was at 6.1 which does not surprise me, I've kept my coco coir PH'd at that level since I started my grow. Now to find some source of potassium. For a source of potassium, could I use a half composted banana peel?

Organics is fine, just be wary of gnats or any other insects it might attract. I love banana and i toss mine outside in the compost pile too

Dremtar said:

Not to hijack this thread or nothing, cause his may be due to PH. I went and tested the ph and it was at 6.1 which does not surprise me, I've kept my coco coir PH'd at that level since I started my grow. Now to find some source of potassium. For a source of potassium, could I use a half composted banana peel?

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Wow! Thanks for the quick replies guys!

Serapis said:

The problem is a micro nutrient deficiency.
...
Any nutrient that has potassium in it will solve the problem quicker,
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Should I be adding bioheaven to the mix (thats all micro-nutrients isn't it?)
Also the bio grow already has a good percentage of potassium (NPK 8-2-6) or should i find something else to use instead?

And I think a pH meter will have to be my next purchase...

Um, that NPK rating has absolutely nothing to do with potassium.......

Serapis said:

Um, that NPK rating has absolutely nothing to do with potassium.......

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Then what would the K stand for? And OP start using your Bioheaven, you need the additional trace and micros.

sorry, I meant to type zinc, as that was the diagnoses...... the potassium is a listed fix, which is indeed the K.... as I stated, this condition is extremely rare, as any good nutrient line has the full range of macro and micro nutrients. I still suspect the PH is farther off than the poster has stated, and that is probably because of the strips.

Thanks again for all your help people!
I'll give it some bioHeaven, see how it goes, and report back in a day or two.
Are these damaged leaves likely to recover from this?

And I'll get myself a decent pH meter!!! It helps to have the right tools for the job!

I agree with the zinc/iron def. But he is using Biobizz nutes. If you use one of them then you better use the entire lineup. Or have other options to fill the gaps......... Ph may or may not be the issue...........

If he is going with a full nutrient line up, no, ph likely isn't the issue... this condition is rare... He stated he is using biobizz and biogrow.... is he missing a 3rd component?

cowboylogic said:

I agree with the zinc/iron def. But he is using Biobizz nutes. If you use one of them then you better use the entire lineup. Or have other options to fill the gaps......... Ph may or may not be the issue...........

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cowboylogic said:

I agree with the zinc/iron def. But he is using Biobizz nutes. If you use one of them then you better use the entire lineup. Or have other options to fill the gaps......... Ph may or may not be the issue...........

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I was hoping to not use bioHeaven until I start flowering as its (relatively) pricey stuff, but clearly it needs some of that heavenly goodness!
I guess thats what happens when you cut corners!
And it would be useful for me to know the pH so I can tell if thats part of the problem... (its a wonder my previous grows went so well without one!!!)

that is def a pH problem. most tap water is between 7-8 pH. it depends how much your nutrient lowers it. but its safe 2 get a meter unless u wanna get slapped at the end of flowering and wasted all the time for nothin.

I am using Grow, Bloom and Top Max in Light-Mix.
BioBizz nutrients have almost zero amounts of Magnesium and Calcium. Make sure these are in your mix. I am battling deficiencies and the results of pH imbalance.
Symptoms are strikingly similar - end of leaf (tip) curl turning grey, but mine are accentuated by Phospohorous deficiency stemming most likely from unmonitored pH.

A digital (liquid) pH meter might be expensive but it's the most important piece in any setup.
The process of elimination; eliminate the potential cause of incorrect pH and you can formulate other hypotheses for perceived problems.

thrash4ever said:

I am using Grow, Bloom and Top Max in Light-Mix.
BioBizz nutrients have almost zero amounts of Magnesium and Calcium. Make sure these are in your mix. I am battling deficiencies and the results of pH imbalance.
Symptoms are strikingly similar - end of leaf (tip) curl turning grey, but mine are accentuated by Phospohorous deficiency stemming most likely from unmonitored pH.

A digital (liquid) pH meter might be expensive but it's the most important piece in any setup.
The process of elimination; eliminate the potential cause of incorrect pH and you can formulate other hypotheses for perceived problems.

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Thanks bro. I think its more of a iron def than zinc. But no matter the causes can be the same. Lack of (calcium and magnesium) both of which are very important in the transport of cofactor enzymes(and the elements)that foster and are products this process. I dont think ph is the issue. The plant just needs a more rounded diet...