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Plants Yellowing!

L

Landing

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For about 10 days now, my plants have begun to yellow at their top.

Now, they've yellower all around and the edges of some of the leaves are more so than the rest.

I thought it was the lights so I placed them higher up.

I feed them a good amount of Bio-Grow.

Also, they don't seem to be growing anymore.. They reached my Scrog screen and sort of stopped..

I'm really worried!

What could be causing this?




 

Hackerman

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Sure looks like my plants when they had a Cal-Mag deficiency. Wait for some other comments but I expect you'll hear Cal-Mag deficiency and, maybe nitrogen, although, I don't think nitro deficiency looks quite like that.

I am going with Cal-Mag deficiency. Let's see what the others say.
 

bwanabud

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I think your PH is out of whack, and/or your water contains heavy PPM of bad juju. If you've been nuting them hard for a while, you could have salt build up also.

How are you checking the PH ?...and what is it ?
 
L

Landing

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Sure looks like my plants when they had a Cal-Mag deficiency. Wait for some other comments but I expect you'll hear Cal-Mag deficiency and, maybe nitrogen, although, I don't think nitro deficiency looks quite like that.

I am going with Cal-Mag deficiency. Let's see what the others say.
Thanks, Hackerman.

It's weird because I had a Cal-Mag deficiency my first grow, before I started using Bio-Grow.

The second grow had no such deficiency so I figured the Bio-Grow was enough.

Before I get some Cal-Mag, is there anything else it could be?

I think your PH is out of whack, and/or your water contains heavy PPM of bad juju. If you've been nuting them hard for a while, you could have salt build up also.

How are you checking the PH ?...and what is it ?
I check my pH with a pH meter. I always add 1ml of pH down to my water and it lowers it to ~6.8 pH.

I'm using air pots so there is always a ton of run-off. Either way, should I flush them?
 

Hackerman

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Looks more like hungry than overfed.

Overfed will usually show tip burn on all leaves. Yours seems to be just on new growth which would more likely indicate deficiency.

Same strain first grow, second grow and this time? Different strains will eat differently.
 

bwanabud

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I'd be running 6.3-6.5, test after adding nutes to the water. Most people aren't going to have that much C-M deficiency at that age,,,sick plants can look like a lot of different things. Start from the ground up first....soil & water problems

Tap or well water ?
 
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You shouldn't need to add Cal-Mag in veg. Does the Biobizz have any Cal-Mag in it? I will say that I do not believe that Bio-Grow really has enough N to be a cannabis vegging nutrient and could very well be causing the yellowing. .

We really don't have enough information to give you a good reply. Tell us more about your grow. It would only be a wild guess without having a lot more info on your grow. What is a "good amount" of Bio-Grow? Are you following the feeding schedule? How large is your room and what type and size of light are you using? How old are your plants? Seeds or clones? What strain? What kind of medium did you plant them in? How old are they? What are your temps and RH? Etc. Etc. The more you tell us about yur grow, the better we will be able to make an educated reply--otherwise we're just guessing.
 

bwanabud

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You shouldn't need to add Cal-Mag in veg. Does the Biobizz have any Cal-Mag in it? I will say that I do not believe that Bio-Grow really has enough N to be a cannabis vegging nutrient and could very well be causing the yellowing. .

We really don't have enough information to give you a good reply. Tell us more about your grow. It would only be a wild guess without having a lot more info on your grow. What is a "good amount" of Bio-Grow? Are you following the feeding schedule? How large is your room and what type and size of light are you using? How old are your plants? Seeds or clones? What strain? What kind of medium did you plant them in? How old are they? What are your temps and RH? Etc. Etc. The more you tell us about yur grow, the better we will be able to make an educated reply--otherwise we're just guessing.
:yeahthat: Exactly right THG, the Bio-Grow is a sugar based nute...with no NPK ratings listed. A lot of things could be going on here, more details are needed,,,I'm still betting PH or water issues :)
 

pcduck

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Most municipal water supplies have plenty of Ca/Mag already in it for vegging plants.
 

Hushpuppy

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I was thinking pH myself. The reason is: it appears that calcium, magnesium, manganese, and possibly potassium are getting locked out. That is usually a very good sign of either pH being way off or salt/nutrient toxicity. Do you test and adjust your water before or after adding the Bio Grow? It is important to know where your source water is on both the pH and the TDS before ever adding anything to it. Then you only adjust the pH after adding the nutrients and allowing them to mix and aerate for a couple hours (at least until you fully know the nutrients and how they act in solution). Do you test the pH of the run-off? It isn't a true representation of the pH within the soil but it can be helpful when compared to the pH of water going in.

What kind of soil are they in? Is the Bio-Grow a synthetic or organic nutrient? How often do you feed with it?
 
L

Landing

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You shouldn't need to add Cal-Mag in veg.
I used GH Flora last time around and they never yellowed out, so I have to assume that it's the Bio-Grow.

What is a "good amount" of Bio-Grow?
3ml/liter.

How large is your room and what type and size of light are you using?
It's 8fx5f.

I use one 1000w and I had it 2f away from the top of the canopy. I heightened it to 2.5f now.

What are your temps and RH?
Humidity is usually between 45-52%.

Temps are 26C at the bottom of the room and 34C at the top of the canopy.

I was thinking pH myself.Do you test the pH of the run-off? It isn't a true representation of the pH within the soil but it can be helpful when compared to the pH of water going in.

What kind of soil are they in? Is the Bio-Grow a synthetic or organic nutrient? How often do you feed with it?
I thought of the pH issue, but I checked it before and after adding nutrients and it's still within the 6.4-6.9 range.

I water my other plants with it and they're doing fine, though they're only 3 weeks old.

Bio-Grow is organic, as far as I know. Certainly so by the smell.

I don't check run-off and I feed as often as I water.

what is a "good amount" ?

what ec/ppm are you feeding at ?

what's the ec/ppm of your tap water ?
I don't have a PPM meter. I just use 3ml/liter. I was told 1-5ml so I took the middle ground.

And I Googled the Top-Max nutrient.. most people said they did better without it so I decided to against it.

I would just like to say to everyone..

There are TWO problems now.

One, the leaves are yellowing and some are burnt at the edges (you can see it in the photos).

Two, the plants are no longer growing! They've simply stopped even though they're in 30 liter containers and are supposed to get a lot bigger.

I waited all this time for them to reach the Scrog screen and now I'm not sure what to do..

Thanks for everyone's help!
 

MR1

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That plant looks hungry to me, try stronger nutes. Your temps are also too high, try to get closer to 25c at the canopy.
 
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I pretty much agree with what multi has posted. Three ml per liter sounds like a small amount, not really a goodly amount. This is especially true when the nutrients have such small N-P-K numbers like the Bio-Grow does. Like I mentioned before, it just seems to be far too little N to maintain cannabis. What do the directions on the bottle say? Are you only using the Bio-Grow? Is it meant to be a stand alone nutrient? It looked like it was meant to be used with a bunch of other things, like the GO products are--I think the GO box contains 8 different things with only 2 of them being listed as optional.
 
L

Landing

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Thanks for the replies, guys.

In regards to the nutrients.. the reason I only used 3ml was because, well.. I'm not sure if any of you have ever used Bio-Grow but that stuff is thicker than maple syrup. You add 1ml and the water turns black!

Also, I remember only using Bio-Grow my first grow, so I figured it would be enough.
I only used Bio-Bloom during flowering and I got great results.

Are there any nutrients I should be using instead of BioBizz? It's just all I know..

And about the temperature.. I don't know what to do about it. With an AC on 24/7 the temps are still only around 32C at the top of the plant.
 

MR1

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Do you have an exhaust fan removing heat from your space?
 
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ALL organic nutrients are like that. Follow the directions on the bottle(s)--it really is not a good idea to try and outguess the manufacturer. Sit down and read all the pertinent information and do what the makers of the nutrients say to do.

Like I asked before--Is this meant to be a stand alone nutrient? It does not appear that way to me. Also, the amount of N is just so little that I am not surprised that the leaves are yellowing.

Do you have an air cooled hood?
 

bwanabud

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Those are some hot temps to be running, sounds like more air flow/exhaust/fresh air is needed. In your earlier post you said 36 deg C....98 deg F is running very hot.
 
L

Landing

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ALL organic nutrients are like that. Follow the directions on the bottle(s)--it really is not a good idea to try and outguess the manufacturer.
Well, the Bio-Grow is really supposed to be stand-alone, as far as I can tell.

There is Bio-Bloom, Top-Max, Fish-Max, etc. but they're for flowering.

Also, like I said, the Top-Max was not favored anywhere I asked.

That's why I'd prefer to change nutrients, but I don't know to what.

Like I asked before--Is this meant to be a stand alone nutrient? It does not appear that way to me. Also, the amount of N is just so little that I am not surprised that the leaves are yellowing.
I'm confused.

The N-P-K of the Bio-Grow is 4-3-6.

It has more N than P, and only second to K. Is that not good?

Do you have an air cooled hood?
Yes.

Those are some hot temps to be running, sounds like more air flow/exhaust/fresh air is needed. In your earlier post you said 36 deg C....98 deg F is running very hot.
The AC is working as intake and I keep it on longer now, so my temps are in the low 90F.
 

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