Yellowing and browning issues in middle of flowering

[abrakota]

Hi guys

As you can see in photos i have some issues in midle of flowering
I grow in soil an autoflower Gorilla cookies
Using a marshydro ts 600 led on 20h on and 4h off schedule
Nutrients that i am using is terra aquatica tri part series (grow-micro-bloom)
i feed according to the schedule with target EC 1.5-1.8 and ph 6.4-6.6
i cant say if the yellowing caused by too much nutrients, but last two feedings i used just ph'ed water.
The problem still exists but i am not sure if i still need to feed her, or keep up with just watering for some days.
Its now day 49 from the day the first leaves appeared.
Any suggestion would be appreciated!

 

[abrakota]

Situation remains the same, i keep up with nutes in full strength according to the company feed schedule.
i am now in middle of week 5 in flower.
give your thoughts please, too close to finish or too close to destroy her?

 

[cpurola]

I am not an experienced indoor grower yet, still on my first run, but maybe the light has something to do with it. I have an AC Infinity ION bar light and I tried to turn it up on my Northern Lights Autos and they didn't like it. Some of the fan leaves started getting pale and I didn't want it to go farther so I backed it back down and they recovered.

 

[abrakota]

You think the light is too close to the canopy?
It has no dimmer at all and its 100Watts

 

[Ninjadogma]

Howdy grower. Looks to me like potassium and calcium deficiency going on, but potassium is a mobile nutrient and calcium isn't. If it's borrowing potassium for its immediate needs, you would expect it to be grabbing it from lower leaves whereas calcium is going to show in place where it's deficient because it's not mobile. Because this is happening mid plant at least as far as the potassium is concerned, it suggests to me you are up against a creeping salt accumulation.

When you are checking EC, are you checking values for both input and runoff? When checking runoff are you producing enough to observe whether it climbs or falls with more water volume pushed through? Sometimes that salt can hide from you if you don't generate enough runoff.

So I would suggest next time you water, push a little water out the bottom working slowly, and after a little has trickled out, collect some, then push a little more water in, collect some more and compare the two. If EC falls on second collection you're good. If it goes up, needs more water until it starts to fall. If EC numbers were low or a healthy number on both collections, you are probably okay to feed.

 

[Ninjadogma]

You think the light is too close to the canopy?
It has no dimmer at all and its 100Watts

I don't see any obvious signs of light stress, no taco-ing or praying and the burnt tips look like they were from nutrients, not light. A 100w light you're gonna need to keep that canopy as even as you can because placement is only about a foot away maybe less for the necessary ppfd. The distance you're running I assume you read the light's spec chart or ran a light meter app because it looks about where I'd expect it to be with a 100w.

I think you've just gotta get that soil more evened out with nutes and you should be good.

 

[abrakota]

Hey @Ninjadogma thanks a lot for your replies and suggestions!
Tbh i never checked the EC of runoff, only of nutes before i feed, so its a good idea and in next watering (without nutes), i will check it the way you proposed!
The lights are adjusted according to my previous experience and also with the support of a light meter app as you well mentioned! 35 DLI and 500 ppfd.
Btw the same led light in previous grows did very good with good yields and quality. (Offcourse i am thinking upgrading it in some point, but i gave it another chance just with this lady).
The strain also, i am growing it for first time!
So you think i measure the runoff EC and maybe i will need a flush if the numbers are high, correct?
If not, i still go with this schedule till finishing off!
Do you think that this condition of the plant will cause a bad quality and amount, or is it reversible??

 

[Ninjadogma]

Hey @Ninjadogma thanks a lot for your replies and suggestions!
Tbh i never checked the EC of runoff, only of nutes before i feed, so its a good idea and in next watering (without nutes), i will check it the way you proposed!
The lights are adjusted according to my previous experience and also with the support of a light meter app as you well mentioned! 35 DLI and 500 ppfd.
Btw the same led light in previous grows did very good with good yields and quality. (Offcourse i am thinking upgrading it in some point, but i gave it another chance just with this lady).
The strain also, i am growing it for first time!
So you think i measure the runoff EC and maybe i will need a flush if the numbers are high, correct?
If not, i still go with this schedule till finishing off!
Do you think that this condition of the plant will cause a bad quality and amount, or is it reversible??

I don't think the plant is too far off kilter by any means to have your harvest affected. The reason for testing input EC is to make sure you're giving a proper dose and not too hot. But you also want to look at runoff EC because that can tell you a lot when you see how the soil changes the value to what you put in with both EC and pH. When your runoff is higher than your input, that's when you have to sit up and pay attention because it can be normal with microbe nutrients contributing to your total EC, or it could mean salt is accumulating. At the end of the day it doesn't matter much, you want to keep it regulated in a healthy range but with a hybrid feed where your using nutrients and growing in soil, it eliminates some dangerous blind spots for you and will prevent you from overfeeding your plant when the biome is extra active.

 

[abrakota]

Many thanks bro, i will update with the runoff EC results in a couple of days when the soil will dry out, and see what is happening!

 

[cpurola]

My thanks too, sorry if I steered you in the wrong direction, like I said still my first rodeo and I'm learning lots.

 

[RGWD0202]

do any of those products contain calcium magnesium or sulfur? Looks like it wants magnesium and sulfur.

Edit: they do contain all 3 of those. I’d recommend making sure you are mixing them in the right order and not over using 1 or more parts. Could be lock out.

 

[LoveGrowingIt]

I think I see some purple color on some of the leaves. If so, that's usually a plant's response to excessive light intensity. Raising the light should help if there's no way to dim it. I'd do that first and wait a few days to see how it responds. I'm not sure about the nutrients, but I suspect they may be excessive.

give your thoughts please, too close to finish or too close to destroy her?

Definitely don't destroy it. It should finish okay.

 

[abrakota]

My thanks too, sorry if I steered you in the wrong direction, like I said still my first rodeo and I'm learning lots.

Nah its fine, i appreciate the good will to help out the situation!

do any of those products contain calcium magnesium or sulfur? Looks like it wants magnesium and sulfur.

Edit: they do contain all 3 of those. I’d recommend making sure you are mixing them in the right order and not over using 1 or more parts. Could be lock out.

The order is micro first, grow and bloom in the end, and i use the same recipe as the chart that i uploaded above.

I think I see some purple color on some of the leaves. If so, that's usually a plant's response to excessive light intensity. Raising the light should help if there's no way to dim it. I'd do that first and wait a few days to see how it responds. I'm not sure about the nutrients, but I suspect they may be excessive.


Definitely don't destroy it. It should finish okay.

I am not sure if this light can hurt her, its too weak i think (100w).
Iwill not destroy it for sure!
Tomorrow probably i will water and i will check what happens with runoff.
Thanks a lot!

 

[abrakota]

So today was the feeding day, and i decided to feed her instead of just watering,
i prepared 3,5Lt of water, mixed up the nutes and ph'ed to 6.5 with an EC at 1.8
Watering slowly until starting to run off the bottom, so i collected a good amount of water in order to measure it
The results was EC 1.78 but ph was a bit higher at 6.8
One thing i never mentioned is that i used dolomite lime( cal:37.8% mag:11.0%), mixing it up with the soil in the start with 1gram/Lt of soil.
I could say that the issue is stable and not getting worse, finishing the week 5 of flowering.
Here some photos

 

[carlosescobar]

I would be interested in how this turns out as i have a layer cake at the moment which looks just the same , healthy but the larger leaves have yellowed but the tip have dried and curled up, and the smaller leaves are turning purple (but i picked layer cake because they purple up at the end) .
you can get led burn from a ts600, i had one of those originally , which i had too close, ..

 

[RGWD0202]

So today was the feeding day, and i decided to feed her instead of just watering,
i prepared 3,5Lt of water, mixed up the nutes and ph'ed to 6.5 with an EC at 1.8
Watering slowly until starting to run off the bottom, so i collected a good amount of water in order to measure it
The results was EC 1.78 but ph was a bit higher at 6.8
One thing i never mentioned is that i used dolomite lime( cal:37.8% mag:11.0%), mixing it up with the soil in the start with 1gram/Lt of soil.
I could say that the issue is stable and not getting worse, finishing the week 5 of flowering.
Here some photos
View attachment 2576640View attachment 2576643View attachment 2576641View attachment 2576642View attachment 2576644View attachment 2576645View attachment 2576639

My understanding is dolomite lime really fucks with the chemistry of soil. If you NEED to use it like a tbsp or maybe even less for 30 gallon container, but might even be less than that. Dolomite does raise the PH so might be why it’s higher than you expected. I’d leave the dolomite out next time. If you need a good cal mag or sulfur cal, gypsum is a great source of calcium and sulfur, langbeinite for mag sulfur. The dolomite can be very funky for plants, th cal mag ratios are out of whack

 

[abrakota]

Yes, i think i shouldnt use dolomite, it was first time doing it! Its the reason of higher ph in the roots clearly!
Maybe i should now on to keep my nutrient mix ph at 6.2-6.3 idk if that will adjust the soil or dolomite keeps rising it!
At the momment no other choice as dolomite cant be removed now!
Thanx for the advice, really appreciated!

 

[abrakota]

Hey growers.. my bad luck is on picks.. my led light stopped working today , its now all day without lights,
if i order one i will probably have it in 2 days.. so 3 days in the dark!
Will it be fine, or i have big issue? Not an option to drive to the shop.. its 3 hours driving there,
and i dont have much time till working time!
I have no other option for light right now, just to order one!

 

[Ninjadogma]

Hey growers.. my bad luck is on picks.. my led light stopped working today , its now all day without lights,
if i order one i will probably have it in 2 days.. so 3 days in the dark!
Will it be fine, or i have big issue? Not an option to drive to the shop.. its 3 hours driving there,
and i dont have much time till working time!
I have no other option for light right now, just to order one!

It shouldn't be a big deal in flower but it will help if you keep the light schedule going with a regular house light until your replacement light arrives. There IS energy for them even with regular light, just not a lot of it. Leaving them in the dark will subject them to a lot of stress by upsetting their circadian rhythm. That's things like the plant perking up an hour before the lights come on... the transpiration cycle, the carbon cycle (CO2 to O2 and then back to CO2)... etc. So if you put a crappy house light in the tent the light isn't ideal, but the plant registers it as light and it will keep up on all the things it does when it gets a light and a dark period.

Your dolomite lime problem, bummer it happened but not the end of the world. Until you can get a downward buffer amended in, you can set your input to a lower number but just know it will creep back up between waterings until you can get it amended with a downward buffer. If you added dolomite for the cal/mag, gypsum and epsom are a better call for cannabis.

 

[abrakota]

It shouldn't be a big deal in flower but it will help if you keep the light schedule going with a regular house light until your replacement light arrives. There IS energy for them even with regular light, just not a lot of it. Leaving them in the dark will subject them to a lot of stress by upsetting their circadian rhythm. That's things like the plant perking up an hour before the lights come on... the transpiration cycle, the carbon cycle (CO2 to O2 and then back to CO2)... etc. So if you put a crappy house light in the tent the light isn't ideal, but the plant registers it as light and it will keep up on all the things it does when it gets a light and a dark period.

Your dolomite lime problem, bummer it happened but not the end of the world. Until you can get a downward buffer amended in, you can set your input to a lower number but just know it will creep back up between waterings until you can get it amended with a downward buffer. If you added dolomite for the cal/mag, gypsum and epsom are a better call for cannabis.

Finally i managed to have a new LED today, but unfortunately i will be able to set it up at night cause of work!
So it will be almost 2 days in the dark, i didnt apply any other light by now so i will keep it up like this until tonight!

As for dolomite i didnt know about gypum or epsom salts, but is there something i could add now to reverse a bit the condition, or keeping buffing the nutrient solution to bit lower ph levels like to 6.0 -6.2?

And some pics with light off