Leaf problem Help me please

[Sanel]

Pot size : 12lt
Ph :6.2
temperature: 83’F
25 plant
4x400 Mh light
Vegation 3 week
moisture: %42

fertilizer:
Sensi Cal-Mag Extra : 2 ml/L
Terra vega. 2 ml
Cannzym : 4 ml/L
Piranha : 0.5ml/L
Nirvana : 0.5ml/L
Bud Candy : 0.5ml/L
Rhino Skin : 0.5ml/L

[Sanel]

what should I do ?

[beardless]

Hopefully someone will correct me if I am wrong but is looks like calcium deficiency to me. Confusing part is I see you are using Cal-Mag extra. Did you start using after first noticing problem?
6.2 ph I assume is ph of nutrient mix. This should be OK for soil. I usually am a little higher like 6.4.
I see you also listed Nirvana and Rhino Skin. They are usually applied during flower.

[Sanel]

Thank you yes i used calmag
What should I do as a solution ?

[Sanel]

I added cal mag

[beardless]

I am only comfortable recommending what AN says to use

Although I use AN OIM products for soil, I have not yet used AN cal mag. I use general hydroponics cal-mag. I have one plant with a similar deficiency and have treated it several times. However, the deficiency persists. This last treatment I used 150% of the recommended dose to see if it resolves the problem.
Are you using coco? (I do not) If you are maybe a lower ph will help.

[Drinkslinger]

It does look like a calcium deficiency. OP is adding cal mag though…

Did you just start adding cal mag or have you been adding all along? Are you using rain/RO/distilled water?

It’s hard to see the rest of the plant. That leaf may have also been in contact with the soil, hence the discoloration.