Need help with this cannabis plant

[Scrizzly]

Hi this is my first grow and have come across a problem with one of my plants.
It started looks off the other day but keeps getting worse and worse.

All my other plants look fine it’s just this one that is lagging behind and looking like something is eating away at this.

The new growth is the yellow and the other leaves are slowly shrinking.

I’ve included some photos so you can see what I mean.

The plants are under a 600 W LED,
temperature is around 75-78
Humidity 30-45%
Watering with General Hydro flora trio at about 20% strength
I ph my water to between 6-6.5

I don’t know if it’s a problem with what I’m giving her or if it’s the plant itself. I don’t know if she will make it much longer.

Any help is appreciated.

 

[Blew Hiller]

Near a fan or light?

 

[Scrizzly]

It’s about about 14 inches from the light,
The fan is about 3 feet and on medium. There are plants that are closer to both the light and fan. So I don’t think it’s light or wind burn as it’s not showing up on any of the other plants.

 

[Emilya Green]

well, you do have a bit of a magnesium deficiency going on and i would recommend adding some calmag+ to your nutes. I get suspicious anytime someone says they pH to 6.-6.5... because that means to me that they are not being accurate. There is a world of difference between 6.0 and 6.5 and it is important to be accurate. 6.3 is where you want to adjust to.
That being said, I don't think that this is the major problem with that one plant. Could it be possible that her roots were damaged upon transplant? Do you have a pet that could have used that container? Something is seriously wrong and she does look like she is dying and I am suspecting something major with the roots... either bugs or physical damage. I have seen this once with severe soil compaction and one plant just couldn't get the roots going but these situations are always very frustrating. I might even be tempted to quarantine this one plant till I knew for sure what was causing this.

 

[Scrizzly]

well, you do have a bit of a magnesium deficiency going on and i would recommend adding some calmag+ to your nutes. I get suspicious anytime someone says they pH to 6.-6.5... because that means to me that they are not being accurate. There is a world of difference between 6.0 and 6.5 and it is important to be accurate. 6.3 is where you want to adjust to.
That being said, I don't think that this is the major problem with that one plant. Could it be possible that her roots were damaged upon transplant? Do you have a pet that could have used that container? Something is seriously wrong and she does look like she is dying and I am suspecting something major with the roots... either bugs or physical damage. I have seen this once with severe soil compaction and one plant just couldn't get the roots going but these situations are always very frustrating. I might even be tempted to quarantine this one plant till I knew for sure what was causing this.

Yes I thought some of the plants looks like they may have some sort of Magnesium deficiency. I have not given any supplement for magnesium. I did order some Sensi Cal-Mag Extra And should have for my watering Thursday or Friday. Will be watering tomorrow as they are starting to need it.
Also I ordered some Ph reference solution so I can make sure my ph pen is Calibrated correctly.
I usually just aim to get between 6-6.5 as I didn’t think it would matter as long as it’s in that range.

As far as the plant that looks like it’s dying. I do have a dog but the plant are in a tent with no way of her having access. I did suspect I had some sort of Fungal or bug infection about 2 weeks ago and I sprayed everything with Safers Brand 3 in 1 Garden spray. The plants that were most affected have since recovered and are thriving.

One thing I also think it may be is a botched topping attempt. I topped 8 of the 9 plants a week ago today. Some of them the top work perfectly but a few of them I didn’t get enough of the leaf and they came out looking deformed. The two on the bottom the top leaves are rounded. But they are still growing.
Possibly the one plant I infected with something when I tried topping it?

 

[Emilya Green]

it may be is a botched topping attempt.

Didn't consider that, but yes... I have seen the results of some very ugly FIMs, and that could very well be it. And yes, 6.3 is very important. Your goal is to be able to slide through the ENTIRE range of 6.3-6.8... it is described as the "range" for a reason. If you come in at 6.3, the soil takes care of the drift. It is a good system, using buffered soil to produce a drift, yet so many people try to second guess it and think that they know some special number within that range that is better than all the others. It is almost humorous how many choose right in the middle, locking out anything needing below 6.5 pH to be mobile.

 

[Blew Hiller]

One thing I also think it may be is a botched topping attempt. I topped 8 of the 9 plants a week ago today. Some of them the top work perfectly but a few of them I didn’t get enough of the leaf and they came out looking deformed. The two on the bottom the top leaves are rounded. But they are still growing.
Possibly the one plant I infected with something when I tried topping it?

If this is the result of a botched topping, I am going to be more careful in the future

 

[Greenlizard]

Perhaps the tool used to top was not clean? Bacteria?

 

[Scrizzly]

Just wanted to give a little update. Never really found out what it was. I ended up flushing the plant and then feeding it. I got some CalMag as well which I didn’t have previously. I also transplanted it the other day as I needed to transplant the rest of the plants as well.
The plant seems to be recovering very very slowly. It has new growth that seems to be coming up green. It’s lagging behind the rest for sure but doesn’t seem to be getting any worse.

I’ll include some photos below:

 

[Emilya Green]

Looking very good now! Look at those leaves reaching up to the light! Good job!