Leaf problems - pics included

[Lester Freeman]

I believe this is could be a zinc/iron lockout due to the pH being too high. The new growth seems to be generally unaffected as well as the budding sites. But I found a lot of leaves that did not look good.
I plan on lowering the pH down to between 6.5-7, does anyone know what would be a good concentration solution to make? I plan on using distilled acetic acid.

Two of my sativas are showing this problem, however my one indica plant shows no problems. All three grown in the same medium. ( I use MG potting soil because its cheap,convienant, and is easy to grow big vigorous plants, the problem with it is that the pH of the mixture lies at around 7.8-8 ( it's great for veg. but, its obviously too alkaline for budding)
So I'm not suprised or shocked by these signs of deficiencies, hoping it will be an easy fix with acetic acid.
Like I said the bud sites look fine and generally unaffected.

I was thinking it could also be nute burn, no suprise there either with slow-release nutes in MG + the organic fertilizer I added, plus tiger bloom ~_~.

Got great bud on my first grow ( got lucky ), so still learning. But I'm definitely not going to mail order special expensive soil. LOL, so will see how they do!

 

[jride129]

Re: Leaf problems, pics included.

hi,
I have sort of the same thing happening, but in my case there are alot more little brown spots and yellowing.
The problem seems to be accending moving from the bottom of the plants to the tops. Do you think that high heat
of 90-95 degrees could do this or nute defficency more likely?

 

[Lester Freeman]

Re: Leaf problems, pics included.

Nah, most likely a pH issue. Could be one or multiple nutes locked out. Refer to Problems/Pests/Diseases --------> Problem Solver/Pictorial

 

[Alkhemist]

heya Lee,

i have used vinegar(acetic acid and water) in the past with flood and drain grows i did a few years ago... i used the vinegar to neutralize my growing medium(river stones) and it seemed to work well, i used around 1 litre of vinegar per gallon of water... im not sure if this ratio would work as effectively for a general purpose ph down tho... the vinegar we have here is around 8% acetic acid per volume of water but my phosphoric acid (ph down) is around 20% phos acid.... so i think it would depend on your acetic acid... will you be using undiluted acetic acid?? or a vinegar?

 

[Buckshot]

Stop!!

If your PH is off by all means fix it and maintain it ... but I don't think that is the issue. I say think 'cause without a whole lot of data and a freak'in lab with folks that know what they are doing I am only guessing. It's based on what happened to a generation of my plants though. I got crazy with the nutes on one generation AND I was using Fox Farms Ocean Forest (great products but they have a huge asshole in customer service) Ocean forest is too hot by itself for some strains and I was pouring on the nutes. It all looked great, I was proud then I started having the problem you are towards the end as I had overloaded on nitrogen and was causing nute lockouts at the end. I did flush and cut my losses (literally) with an early harvest. I have since started using Happy Frog soil and really reducing the nutes but add folier feeding during veg with dyna-gro foliage pro and I have turned it around.

I don't have leaf shots but you can see some damage here

After I got it right

 

[Lester Freeman]

heya Lee,

i have used vinegar(acetic acid and water) in the past with flood and drain grows i did a few years ago... i used the vinegar to neutralize my growing medium(river stones) and it seemed to work well, i used around 1 litre of vinegar per gallon of water... im not sure if this ratio would work as effectively for a general purpose ph down tho... the vinegar we have here is around 8% acetic acid per volume of water but my phosphoric acid (ph down) is around 20% phos acid.... so i think it would depend on your acetic acid... will you be using undiluted acetic acid?? or a vinegar?

I'm not sure even if it will work, since it won't be buffered the pH should bounce back up to where it was. I was planning on using distilled acetic acid ( white vinegar) - best you can get. But I'm unsure on the concentrations. 1liter per gallon seems WAY too concentrated. I don't know what to do to lower my pH to allow more nutes in.

 

[Lester Freeman]

Or like Buckshot said a nute toxicity.. but from the pics compared to the pictorial it looks like multiple metal defiencies, which isnt suprising considering my pH is pretty darn high for flowering.

Hopefully it doesnt get too bad.