Hello everyone!
These brown spots/rust what are they? I already gave calmag last week but it didn’t stop.
There are 4 dwc plants in my grow tent, all with the same feeding. This is the only plant with problems, the others are healthy so its probably strain related.
What’s your opinion?
Thanks in advance!
DWC + LED Lights
Strain: Acapulco Gold from Barney’s Farm
Nutrients: Silicon + CalMag + Ionic Bloom + PK Boost
pH: 6
EC: 2.0
No expert here, but I checked my cannabis bible, only things resembling that is zinc deficiency, nute burn or heat burn
Could your potassium be a little high? I had something similar lately and that was the cause for me.
I would increase the airflow and try to keep temps as low as possible. Check the distance of your lights. This will ensure that it isn’t heat/circulation issues. The next thing I would do is refrain from any fertilizers for a couple of weeks to flush the roots a little. Then slowly introduce your nutes back into your regimen. Maybe 1/10 strength at first, then 1/8, 1/6 etc. this should take care of the problem. They are looking very healthy overall. Follow these instructions and you will have a lush, green canopy. They are beautiful man 
Imho i think its a phosphorus issue. Id do a flush n drop your ph to 5.7.
I decreased EC from 2.0 to 1.2.
Someone advised me that plants in hydro don’t need too much EC. Let’s see what will happen.
I think its more than one looks like excess P and K
drop the PK boost, you could then run 1.4-1.8 EC
I also agree with @Skiball your PH is too high
