Northern Lights Help!

[autoflowah]

Hey all, am currently growing an Auto northern lights indoor, 300w LED, in a grow tent with extraction fan and an internal fan for airflow.

1) Recently a lot of its leaves grew a lot seemingly overnight, particularly the leaves on the main Colas. They also look “loose” in shape versus average leaves, and too big, especially as the plant had been flowering for some time.

2) Today I got it out out for some maintaince and a lot of the leaves are turning very light green/yellow (perhaps nitrogen under feeding), especially on one side of the plant (more directly below the light).

3) When inspecting the top leaves they looked like this today, almost brown and thin.

Any advice on what’s causing all the issues would be really approached from the experts?
Thanks in advance.

 

[Mañ'O'Green]

I cannot open the picture? Please post some more. I will move this to the infirmary for better response in the meantime
Please fill in this form: (copy and paste part is below, this first one tell what specifically to include)

-Problem: (brief description)
-Medium/grow method: soil; soilless-- coco, or peat based like Promix, etc. (please provide the actual product name); DWC, NFT, etc.
-Feed and supplements used: include brand, dosage/strength, frequency of feeding and watering (alone); method-- by hand, drippers, rercirc' or drain-to-waste,... N-P-K #'s too if you can!
-Water source: RO/DI; tap- dechlorinated-?..... EC or TDS reading; pH (don't bother with this on RO/DI, do bother with TDS/EC though to confirm it's working well enough)
-Strain and age
-Climate: night and day ambient T and RH%; res' temperatures; any extremes in T/RH% exposure
- Light used: HID, LED, COB, combo of,... wattage; light cycle hours (20/4, 18/6 , etc.); distance to tops....
-Additional info: PH in the root zone. How long have the plants been affected?...How fast did symptoms appear?... Anything else you think might be relevant..

--Pictures including WHOLE PLANT PICS, and troubled leaves.. use normal light or flash as other light sources ruin color rendering, critical for diagnostics!

✂ - - - - - - - - - - -
(copy and paste)-->

Problem:

Medium/grow method:

Feed: and supplements used:

water source:

Strain/age:

light used:

Climate:

Additional info:

 

[autoflowah]

Thanks for the quickly reply, I think the pics should work now!


Problem: leaves have started to regrow mid flowering, quite large versus cola buds. Fam leaves turning quite yellow on one side, facing light, and leaves also looking brown and limp on the top.

Medium/grow method: Organic soil with drainage supplements.

Feed: and supplements used: currently using plant magic old timer bloom organic fertiliser at 1mg/L every other feed, watered every 2 days, alternate fertiliser/none. 3-5-4, mixed with water.

water source: Tap, left to settle for 24hours and PH’d

Strain/age: Auto Northern Lights, 8-10 weeks

light used: 300w LED, 18-6, 4-6inches from top

Climate: 26 degree around 45% RH, warmer this weekend given weather. 22 45% at night

Additional info: started over the past week or
So, only noticed damaged leaves today

 

[Olderfart]

Is that 300 real watts, or HPS equivalent? If real watts, part of your problem may be lights too close.

Also, your plant may be hungry. If your pot is on the small side, the lady may be running out of nutes, and the organic nutes you are adding may not be available quickly enough to fix the shortage.

Finally, it is also possible that you have a pH lockout going on.

I am new at this so take my comments as head scratching until one of the gurus shows up. @Waira is your man if you can raise him.

 

[autoflowah]

Is that 300 real watts, or HPS equivalent? If real watts, part of your problem may be lights too close.

Also, your plant may be hungry. If your pot is on the small side, the lady may be running out of nutes, and the organic nutes you are adding may not be available quickly enough to fix the shortage.

Finally, it is also possible that you have a pH lockout going on.

I am new at this so take my comments as head scratching until one of the gurus shows up. @Waira is your man if you can raise him.

thanks for the tips, this is the light, I assume its not the best quality, first timer here

Amazon product ASIN B07DC9WZ8W
RE nutes and pot size, it’s a 22L tub so not sure it would be that?

I think the PH is right but my tester isnt great.

any chance it’s to close to the light with that lamp? Seems to have Happened quickly perhaps when it got too hot over the weekend

 

[Olderfart]

The Amazon writeup says this is a 100 watt light, which might be the case. I would guess in reality it is no more than that, but at 100 real watts, it is still possible that you are a bit close at ~4-6 inches. However, I seriously doubt that the color of leaves other than at the very top of the plant are related to light intensity.

My bet is that the nutes are running out and your organic nutes are too slow to keep up. A 22 liter pot may be a bit small to feed a plant as slow as Northern Lights without adding some quickly available nutes once the lady gets hungry during flowering. Just a guess on my part though, so you should probably wait until one of the gurus get back to you.

The other main possibility is a pH issue, but given that you are trying to make an organic grow work, the fix is not easy. In coco or Promix, I would flush with properly pHed nute mix until the runoff is within specs, but with organic soil, this would flush the organic nutes out of your medium.

Absent more expert advice, I would in your boots consider flushing with pH'd synthetic nute mix until the runoff is where you want the soil to be. This would commit you to finishing the grow with synthetic nutes, but that may be preferable to having the lady shut down before she is done. Given the entirely white pistils, you are still weeks from harvest, so you have a way to go yet, and you need to keep her somewhat happy for that long. If the current leaf problems are getting worse quickly, you may be forced to correct one way or another in order to finish.

Sorry I can't be more specifically helpful, but I am new at this too. If you hang in there for a couple more days, I expect that one of the expert growers here may have better advice for you.

Good luck with it, I will be interested to see the other advice you get, and how you make out with it.

 

[Mañ'O'Green]

Do you have a fan moving air in the grow space? and is it possible the Temp/RH is getting lower or higher than you think? The nutrients can be in the soil but if the plant is not transpiring because the stomata are closed it cannot bring them in.

They talk about some IR in that light and that can burn. Check for a defective chip hold a piece of white paper right up against the light for a few minuets to see if it is strong enough to burn it. If not then the 6 inch minimum in their advertisement is probably true.

I think running organic soils is more challenging than any other style of growing. If it is not environmental or PH then that leaves available nutrients. You may need all three macro nutrients N-P-K and magnesium. The fastest acting organic fertilizer is human urine. Whether or not you want to use it is another story. You can read about it here:

Urine: the ultimate 'organic' fertiliser?

Your bladder's loss could be your vegetable garden's gain, since urine makes for a surprisingly good fertiliser - so why are we wasting our wee?

theecologist.org

You have to admit it would be faster than an Amazon delivery .

 

[Waira]

- Hey bud! ...... Looking at the whole plant, I'd say part of the problem is a low level of nutes long term, just not quite enough to cover the bases and demands; lack of P and micronutes stands out, but that's just a visual assessment; many are linked to others for proper uptake and metabolism, so the bottleneck could be any number of things, and can't be determined really,...
Top does look cooked a bit, LED doesn't burn- literally - but it can easily overload the photosynthetic machinery in there... Raise the light up to a foot at least....
...in-pot soil pH is what you really need to know, since pH of water/feeds going in doesn't reflect that at all... If it's off, you may have a lockout going on... the hitch is, I doubt you have a good soil pH probe handy, an often overlooked tool in cannabis growing. Hitch#2, not knowing if the pH is off, and feeding more, may make matters worse, not better! A last resort is the run-off test of pH, using just plain water, which should be RO/Di/very low ppm because mineral content in tap may skew ph readings, part of the inherent errors in run off testing,... We do have an "improved method and calculation" in the Sticky section above this one, read that and consider.... Last hack is to just do a watering with RO/Di and collect the first half cup of run-off and pH test that.. while it's very unlikely to be accurate to in-pot pH, if it's way off we at least know the pH is wonky and in which direction (acidic/basic)....
Your pH meter, well cared for? Calibrated, stored in the right solution, never dried out? Some have a little sponge in the cap to put storage soln. in to maintain the electrode bulb....