Rust spots appearing

[Ganjalf the Green]

Hi there,

Just wanted to check if i'm dealing with this correctly. I noticed the slightly yellowish tint a few days ago and drew the conclusion that it could be an under-watering issue so i upped it slightly, today these rust spots started appearing. My uneducated guess after some research points at late stage potassium deficiency. I upped the nutes a bit with hopes that this will pass

It's growing in coco coir / vermiculite / leca mix in about 5,8-6 ph under a 200W LED.
Temp 21-23c / 50% Rh

Cheers !

Running these nutes according to the plan. I noticed the the dosage ramps up during the first three weeks and that i might been a week behind. Might be part of the reason perhaps.

 

[nickeluring]

It could be a Calcium deficiency. It's common with Coco and LED.

 

[Ganjalf the Green]

It could be a Calcium deficiency. It's common with Coco and LED.

Thanks for the swift feedback.

Update: Dropping one of the secondary leafs. The rust seems to have slowed down a bit post my +dose.

This seems fine. ( Dr Grinspoon or White Widow, Got them mixed up.)

And this too (Again not sure if this is the sativa...broader leaves suggest Indica but i'm a bit to novice to tell )