Please help! 5th week into flower

V

vexstar

New Member

Hi all,
I have an issue of some kind and don't know what I'm looking at.

A brief description of my setup and a problem :

Unknown strand, cloned
Soil : very good quality, used before
Lights: 180w LED, 6x18w T8
4 weeks + 2 days into 12/12
Temp: 28,5* C day, 21* c night
Humidity : 40-45%
Ph: cca 6-6.5, analogue
Ferts: none until week 4, then organic algae mix, molasses, organic amonium, amino+vits in grow
Flower: P-K, 28-26, organic, +molasses+ amino+vits

Week 5 grow-until week 3 flower : 3-4 times / week, foliar feed, microelements

Since 10 days ago, lower fan leaves first yellowed, then dried and were easy to pull of. Now, upper fan leaves are getting pale green, yellow if you will... new growth seems unaffected, although I recon it may have looked better. And I wonder, WTF? The affected leaves are firmly in place, yet look 'exhausted '. What is wrong with my babies? 2 out of 4 look hit, other 2 are in much better shape...

Ph is measured by approximate scaling, yet I'm constant in doing it. I flushed once when switching to flower. So far, no issues at all.



Pics attached. Please help!

IMG_20150223_194719.jpg
IMG_20150223_194642.jpg
IMG_20150223_194546.jpg
IMG_20150223_194522.jpg
 
Like go4snypr said, it's hard to tell with purple pics. Try and get a picture with natural light. 5 weeks in is about the time that you see Nitro deficiencies during flower. Just means the plant wasn't given enough during the veg period.

vexstar said:

new growth seems unaffected, although I recon it may have looked better. And I wonder, WTF? The affected leaves are firmly in place, yet look 'exhausted '.
Click to expand...

This is because the plant is sucking the Nitrogen from storing to promote new growth. You can try supplementing Nitrogen to stop it from using up all its stored N. But it wont do anything to correct the leaves that are already yellow
 
Nitrogen is a mobile element, you will always see older growth affected first. It sounds like go4snypr was right on the money.

For my own knowledge, what is 'approximate scaling' when used in reference to PH?

Flushing before Flower is a great move, it flushes away any built up salts, cleaning up the roots, and allows them to really absorb nutes and help the plant explode with growth in Flower. Great job!
 
Antics said:
Nitrogen is a mobile element, you will always see older growth affected first. It sounds like go4snypr was right on the money.

For my own knowledge, what is 'approximate scaling' when used in reference to PH?

Flushing before Flower is a great move, it flushes away any built up salts, cleaning up the roots, and allows them to really absorb nutes and help the plant explode with growth in Flower. Great job!
Click to expand...

Thank you and all before you...

I'm measuring Ph by taking the sample and colouring it by Lakhmus, then comparing the shade of coloured sample to a scale :). So, it is approximately accurate, but it is consistent - I'm just mentioning it - since I've never seen what leaves look like if Ph is an issue.

I've also read about organic nutes, not being sufficient in 'power' as synthetic nutes are in comparison...

So, I'm in doubt - should I add N in this phase? Or is this N deficiency expected and should be ignored?

What would you do?
 
Ah ok, I used those before as well. I find the digital PH meters are much more grower friendly, since they will count in .1 increments, so we can see our 6.5 exact PH for soil, and 5.8 for hydro.

I would suggest that you do occasional tests on your water, and always test your water/nutes and correct the PH before feeding. Occasional runoff tests will let you know that your soil is doing good. But the more often you can check these things, the better off you are.

Organic nutes, when properly used with a rich organic soil will be just as good as any other nutes. Some growers here make soils that need no nutes at all :)

It really depends on how bad the problem is. We still haven't seen a clear picture to definitively diagnose the problem. Nitrogen was suggested based on descriptions given by you, but there are multiple issues that can show similar symptoms.

As soon as you can, get a picture without the LED on and just use normal light so we can help you get this fixed.
 
I did measure water Ph, I still do - and it is constant at cca 8.5. So it's rather an alkaline medium. I leave water to rest for a day before watering, measuring Ph after mixing my magic into it.

So, if not N, what could it be? I once had a Mn issue with one if my babies in grow period, but it looked completely different, I fed her foliar and she was on 100% in no time....
 
Zinc deficiency because of the bright green veins and yellow leaves, it'd be the first nute to get locked out if ur pH is too high... Get a pH pen as those test kits aren't accurate enough.

Nitrogen deficiency makes the entire leaf go yellow including the veins.
 
Ph - is not issue, if it was symptoms and issues with it would appear in past. Water is constant with its Ph, my measurements as well, and my Ph correction is always identical with same scores

Zinc def - i doubt, since Zn is not mobile so new growth should be affected - but it's not, leaves are not deformed / distorted
Phosphorus def - strongly doubt, i have no necrosis/dark spots on leaves nor other typical symptoms of it

Can I rule out microelements defs, since I'm regularly foliar feeding my babies with a cocktail of such micronutes?

If yes, this issue is left with only N as possible deficit nute -> if so, should I add some in this stage of flowering?
 
:)

I'm just trying to use logic in diagnosis, nothing else...

I'm aware of possible issues when using chosen Ph testing - but.... don't you think i should experience Ph related issues in previous months then? Why now, out of the blue, there should be issues with Ph being out of range?

I did not change anything else except nutes mix....and dosage, of course.
 
Given Ph at 6.5 and assuming uptake of nutes is OK, lofty dosage of P-K added -> Phosphorus deficiency ruled out.

Was studying all possible pics of P def, found on web, and I believe that P is not an issue.

But since I'm only human, please correct me if I'm wrong :)
 
Using a pH color test kit would give you a general reading between 6.0 and 7.0. that's a huge difference when it comes to nutrient absorption. And adding or subtracting nutes will change the pH of the solution without necessarily changing the color of the pH test strip.
 
vexstar said:
:)

I'm just trying to use logic in diagnosis, nothing else...

I'm aware of possible issues when using chosen Ph testing - but.... don't you think i should experience Ph related issues in previous months then? Why now, out of the blue, there should be issues with Ph being out of range?

I did not change anything else except nutes mix....and dosage, of course.
Click to expand...

Because the plant was not looking for as much of that nutrient at the time. if your ph is out a bit but the plant is not looking for a bunch of that nutrient you wont see the deficiency. Once it wants that nute but it is not available because the ph is a bit too high or too low then you will start seeing the effects.
 
vexstar said:
Given Ph at 6.5 and assuming uptake of nutes is OK, lofty dosage of P-K added -> Phosphorus deficiency ruled out.

Was studying all possible pics of P def, found on web, and I believe that P is not an issue.

But since I'm only human, please correct me if I'm wrong :)
Click to expand...

adding nutes makes them available but does not mean they are being used. If your ph is too high or to low, or if you have an abundance of another nutrients you can lock out nutrients. Flush them, and then feed at 1/2 strength, then go back to regular feedings. also what is already yellow will stay yellow.
 

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