# Plants Yellowing!



## Landing (Oct 8, 2014)

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?


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## Hackerman (Oct 8, 2014)

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.


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## bwanabud (Oct 8, 2014)

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 ?


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## Landing (Oct 8, 2014)

Hackerman said:


> 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?



bwanabud said:


> 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?


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## Hackerman (Oct 8, 2014)

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.


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## bwanabud (Oct 8, 2014)

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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## The Hemp Goddess (Oct 8, 2014)

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.


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## bwanabud (Oct 8, 2014)

The Hemp Goddess said:


> 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


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## pcduck (Oct 8, 2014)

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


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## Hushpuppy (Oct 9, 2014)

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?


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## Landing (Oct 10, 2014)

The Hemp Goddess said:


> 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.



The Hemp Goddess said:


> What is a "good amount" of Bio-Grow?



3ml/liter.



The Hemp Goddess said:


> 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.



The Hemp Goddess said:


> 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.



Hushpuppy said:


> 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.



multifarious said:


> 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!


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## MR1 (Oct 10, 2014)

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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## P Jammers (Oct 10, 2014)

FEED ME​


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## The Hemp Goddess (Oct 10, 2014)

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.


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## Landing (Oct 11, 2014)

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.


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## MR1 (Oct 11, 2014)

Do you have an exhaust fan removing heat from your space?


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## The Hemp Goddess (Oct 11, 2014)

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?


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## bwanabud (Oct 11, 2014)

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.


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## Landing (Oct 13, 2014)

The Hemp Goddess said:


> 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.



The Hemp Goddess said:


> 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?



The Hemp Goddess said:


> Do you have an air cooled hood?



Yes.



bwanabud said:


> 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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## bwanabud (Oct 13, 2014)

Landing said:


> The AC is working as intake and I keep it on longer now, so my temps are in the low 90F.



That is WAY too hot


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## The Hemp Goddess (Oct 13, 2014)

The Bio Grow that they sell here is 8-2-6--which is a much better N-P-K ratio for cannabis:  [ame]http://www.amazon.com/dp/B004SWWZ22/ref=asc_df_B004SWWZ223315158?smid=ATVPDKIKX0DER&tag=pg-1148-86-20&linkCode=df0&creative=395097&creativeASIN=B004SWWZ22[/ame].  

I think the lack of green is a lack of N.


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## Landing (Oct 13, 2014)

bwanabud said:


> That is WAY too hot



You said that 98 was too hot so I got it down to 90.

Now you're saying that THAT is way too hot?



The Hemp Goddess said:


> The Bio Grow that they sell here is 8-2-6--which is a much better N-P-K ratio for cannabis:  http://www.amazon.com/dp/B004SWWZ22...e=df0&creative=395097&creativeASIN=B004SWWZ22.
> 
> I think the lack of green is a lack of N.



This is the one I bought. I'm not sure why there are two..
[ame]http://www.amazon.com/BioBizz-BBG1L-1-Liter-Bio-Grow-Organic/dp/B005PX47FG/ref=pd_sbs_lg_2?ie=UTF8&refRID=1DJ42TB0PXXTEAYKTTVD[/ame]

So, what should I get instead?


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## The Hemp Goddess (Oct 14, 2014)

You can usually get away with the temps getting into the low 80s, but anything above that is going to cause problems.  Tell us exactly how your ventilation is set up and maybe we can make suggestions to help cool things down.  If you are running A/C, you should be able to get temps lower.


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## Landing (Oct 15, 2014)

multifarious said:


> 90ºF is way too hot!
> 
> You need to get your temps in check (72ºF - 76ºF , 22ºC - 25ºF)



That's impossible in the summer. I could run the AC 24/7 and it wouldn't get to 25C max.



multifarious said:


> you could try Fish-Mix for a N boost



Are you serious?!

Bio-Bizz recommends* taking out* Bio-Grow for the GROW phase?

These people are idiots. They should call Fish-Mix Bio-Grow or else they're bound to mislead thousands of growers like myself.

You see, this is why I need new nutrients. I just can't trust BioBizz anymore.



The Hemp Goddess said:


> You can usually get away with the temps getting into the low 80s, but anything above that is going to cause problems.  Tell us exactly how your ventilation is set up and maybe we can make suggestions to help cool things down.  If you are running A/C, you should be able to get temps lower.



I managed to get temps down to 29C but they won't go any lower than that.

Also, this is at the TOP of the plant, right under the lights. I seriously doubt most growers measure their temps that high.


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## Landing (Oct 15, 2014)

UPDATE:

After going back to using GHE Flora (at twice the recommended dosage) my plants have gone back to a healthy shade of green.

I would like to thank everyone here who helped me discern that it was malnutrition that caused the yellowing and lack of growth.

And as a warning to all growers out there - NEVER use Bio-Grow by itself.


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## bwanabud (Oct 15, 2014)

My indoor temps fluctuate between 18-24C here, we have outdoor temps of over 37C.

If you don't control temps and airflow, you'll be fighting a loosing battle. Heat stress & fluffy buds will be in your future....and possibly hermies.


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## zem (Oct 15, 2014)

Landing said:


> That's impossible in the summer. I could run the AC 24/7 and it wouldn't get to 25C max.
> 
> 
> 
> ...


you do not place the thermometer under direct light, just like you do not put it under direct sunlight as it will give inaccurate reading


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## Landing (Oct 16, 2014)

bwanabud said:


> My indoor temps fluctuate between 18-24C here, we have outdoor temps of over 37C.
> 
> If you don't control temps and airflow, you'll be fighting a loosing battle. Heat stress & fluffy buds will be in your future....and possibly hermies.



You must have a really powerful AC, then.

Mine is 1600 watts and it could never reach 18C with two lights, let alone three.

Problem is, more powerful AC = more suspicious.



zem said:


> you do not place the thermometer under direct light, just like you do not put it under direct sunlight as it will give inaccurate reading



Then where should I place it? The whole room is under light.

Also, wouldn't the light factor into the heat making it MORE accurate?


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## zem (Oct 16, 2014)

Landing said:


> Then where should I place it? The whole room is under light.
> 
> Also, wouldn't the light factor into the heat making it MORE accurate?



you should place it on the side of your grow space just above the top cola where the light doesn't strike it directly. in greenhouses we place them in the shaded areas. the light factor does not make it accurate because of heat buildup due to constant bombardment by direct light waves, for example, if you stay in the sun on a cold day, you would feel warmer although it is very cold


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## Landing (Oct 16, 2014)

zem said:


> you should place it on the side of your grow space just above the top cola where the light doesn't strike it directly. in greenhouses we place them in the shaded areas. the light factor does not make it accurate because of heat buildup due to constant bombardment by direct light waves, for example, if you stay in the sun on a cold day, you would feel warmer although it is very cold



Right, but aren't the plants getting the same heat buildup since they're under the light?

If you measure it under the plant, you'll never know how much heat the plant is getting.


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## zem (Oct 16, 2014)

the plant naturally deals with the heat buildup. when they say plants thrive at temps of 22C they actually mean 22C in the shade and not in the sun. weather forecasts and all temp recordings are taken this way


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## MR1 (Oct 16, 2014)

I take my infrared thermometer and aim it at the top of the bud right under the light, that is the measurement I use, then adjust height of light, ventilation etc. to get to the temp I want.


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## Landing (Oct 16, 2014)

So then, 35C under light is not bad, right?


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## MR1 (Oct 16, 2014)

24c is what I shoot for, 28c is as high as I will go. That is just me though.


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## Landing (Oct 19, 2014)

MR1 said:


> 24c is what I shoot for, 28c is as high as I will go. That is just me though.



Right, but how much would that 28c be if it was in direct light?


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## zem (Oct 19, 2014)

in direct light it will not give an accurate reading. the closer you get to the light the higher the heat exponentially, so really, no one can answer to your last question, 28 is just that, 28


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## Hushpuppy (Oct 19, 2014)

The plants can take the "radiant" heat that comes from the light if the "ambient" temperature is low enough so that when the fan that you have on the plants blows across them, it cools them to the level of the ambient temperature. 

The "ambient" means the temperature of the air itself. "Radiant" heat is the energy that is held within the photons of light coming from a light source. When those photons strike a surface or pass through a resistance, they will release some of their energy as heat. The plants have a unique ability to absorb some of that energy so that it doesn't release as heat. That ability is photosynthesis. However, some of the energy from the photons isn't able to be absorbed so it does get transformed into heat. Some of that heat radiates back into the air and some stays within the leaves. The plant responds to the buildup off heat the same way we do, by sweating. Its not called sweating in plants, it is called transpiration, but it still a release of water which carries away some of the heat from within the plant. 

If there is a good enough breeze blowing across the plant, both the re-radiated heat and the transpiration will be carried away on the breeze. However, if the ambient temperature of the space gets too high, the plants struggle to release that inner heat and will begin to shut down certain functions.

Now when you measure the temperature of a space, you are measuring the ambient temperature (or the level of heat energy that is in the air) This is done through direct contact of the heat energy in the air with the temp measuring device). But if your thermometer is in direct light, it is getting the contact energy from the air AND it is getting radiant energy from the photons of light that is hitting it and releasing the energy within those photons as heat. At this point you art not accurately measuring the "ambient" temperature, which is what we use to determine the level of functionality for the plants.

I hope all this makes sense for you.


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