HELP! Leaves slowly dying

[Mjmjm]

Hello you guys. The problem started with the bottom leaves. On day 12, the bottom leaves started changing in appearance and within 1 week they were already dead. By day 20, 3 of the newer leaves got affected, i have the evolution pictures of the problem when it was forming on the second set of leaves: first they darken (one half or one third of the leaf seems darker than the rest of the leaf) with a clear limit/line to the end of the affected area. The affected area then starts crumpling and gradually turns yellow, dries off, and dies. Also the plant's growth seems very slow and it has been stagnant for the past 2 or 3 days.
It's a royal gorilla automatic
In the vegetative stage: 3.5 weeks
Medium: coco + perlite
Nutrients: CalMag with the water and easy grow mixed in the growing medium (60g mixed with 16 liters of coco and perlite)
Light schedule : 20 hours on/4 OFF
Temperature: 20 - 26 degrees celsius
Humidity: it was around 70%, i got a dehumidifier and now it's around 55%.
PH of the water given to the plant: 5.5 - 6
PH of the water coming off from the plant (drainage): 7.5 - 8.5

[duckman]

at first glance it seems like your pH is wonky, maybe a lockout...what is easy grow?

[JohnEmad]

that ph runoff is very high for coco/perlite.

[SoOrbudgal]

light/heat issue

[Mjmjm]

Yes the drainage water pH is high indeed, but I can't figure out why. Thoughts?

[JohnEmad]

Hi Mjmjm, welcome to the GWE forum,
I don't know anything about Easy Grow nutrients but the high ph coming out could be related to how strong the nutrient solution is.
I usually start at a 1/2 strength or even lower concentration and gradually increase it as the plants grow and start to use more.
A nutrient build up can easily raise the ph and cause a lockout.
If this is the case then a flush with ph'd water may be required. Checking the runoff until it shows acceptable ph levels.
here is a great article on flushing.

https://www.growweedeasy.com/flushing-sick-cannabis

[Mjmjm]

The instructions of use say to mix 50 to 100 g per 10 L of substrate.

[gbauto]

Because the lower leaves have developed chlorosis, I'd say it's the plant's response to a nitrogen def.
Like JohEmad has said, you need to treat coco like your running a hydroponic system. The medium has virtually no nutrient storage capacity like soil so the roots need to have access to nutrient solution 24/7.
Can you give us some more info on how you're watering

[Mjmjm]

I did mix nutrients in my coco. I have a photo of the nutes bag attached in a separate comment under the post.
I'm also adding calMag to the water and watering every 2-3 days, giving ~1L at a time

[SoOrbudgal]

Over fed to young

[duckman]

those nutes mixed in the soil make me real nervous...

[gbauto]

Exactly.
It's going to be almost impossible to maintain a desired nutrient concentration when you have 'nute bombs' throughout the media.
I think that you'll get much better results if you dissolve the mix first in a known volume of water.

[homegrown]

Here's an option..If you have anymore coco/perlite, fill up another container with just that mix alone(no fert or nutes). Take both hands and scoop out that plant and settle it into the clean fresh batch of coco. That way you wont have to piss around trying to get your current soil mix back into the proper ph zone. And you plant doesnt have to fight that hot soil mix.. She may perk up pretty quick. Flushing will probably work but your gonna slow everything down for at least another week before the pot dries out enough that you can resume a feed schedule. Its easy to increase nutes, but shit hits the fan if you go overboard.