Calcium deficiency?

[Duppy]

Hello,

two days ago I discovered a few brown spots on the upper leafs of one of my Early Queens. As I'm not sure what exactly causes this problem, I want to ask you guys.
Is it a calcium deficiency, what do you think?

Medium: dirt
Nutes: Bio-Bizz (Bio-Grow, Bio-Bloom, Alga-Mic, Top-Max)
Water ph: 6-6.5
BD: 35
Lamp: Gavita Pro 6/750e DE Flex

Thanks for your help in advance!

 

[NebulaHaze]

Yes, that looks a lot like a Calcium deficiency to me. Can you get your hands on a Cal-Mag supplement? It can help stop it from spreading to raise your light a few inches until you get a supplement (so the leaves aren't working as hard). Just don't go overboard since you're in the flowering stage, maybe use it at half strength. Overall your plants look great!

 

[9fingerleafs]

Couldn't it be a symptom of a greater problem? looks very severe to be in soil and regularly feed

 

[9fingerleafs]

Like potassium toxicity leading to calcium lookout? Or salt buildup on the medium?

 

[Duppy]

Thank you!
I gave them a little rock dust, but I'll try to get some Cal-Mag as soon as possible. And thanks for the tip with the light.

 

[NebulaHaze]

I'm not familiar with giving rock dust to cannabis, but I agree with 9fingerleafs that it's good to also be aware of anything else that might be causing symptoms of lockout! And also to watch your plants to see if they react positively or negatively to the rock dust