Deficiency identification, help pls

[UBU ROI]

So, i was searching for some similarities on different charts online, but i found nothing like it. Could u please tell me if that is a nutrient or Ph deficiency?

Thank you.

 

[Antics]

Soil or hydro?

What is the PH right now of your medium?

 

[UBU ROI]

Outdoor grow, soil, its a mix made of local outdoor soil and plagron light mix. its my first time growing, Im aware that right ph is essential for proper dissolution of nutrients, but i havent checked it yet since i havent managed to buy a ph meter. i intend to do that asap.
i would like to add that i have other plants near by, planted in the same soil mixture, but they don't show such deficiencies. They were transplanted 2 weeks ago and i havent used much additional nutrients so far.

 

[Antics]

It almost looks like a Phosphorous deficiency.. Plant and Pest Problem Solver

But you have to get a PPH meter and check the soil ASAP. Don't add nutrients until you know the PH. Doing so can kill your plants in short order if the issue is just PH lockout, and your soil actually had plenty of available nutrients.

The other 2 plants you mention, are they Cannabis, or another plant?

You also said the other plants were transplanted 2 weeks ago, how long has the trouble plant been there?

How often are you watering? How often are you feeding nutes?

How old is the plant in question?

 

[UBU ROI]

according to the pics on your guide, those black spots on my plat dont talk in favor of your diagnosis, do they?

yes,the other plants are cannabis aswell, just different strains.

the problem was spotted today. i cant exactly say when it started, but id say around 4 days ago. Only few big leaves are damaged though.

Im watering when necessary, 2-3 times a week in general, depends on the weather and soil moisture, ofc. It was quite rainy that week so i didnt have to water much.

Plants havent recieved any additional nutrients since i planted them outdoors. When still in growbox, i added nutes once per few days or less, always minimum dosage, cause i didnt want to over do it.

I started with germination at the beginning of march. The plant is 2 months old. Its a critical+ Dinafem strain.