Is there anything else that you can tell about what's going on?
I'm not following the conversation so I'll just add some info.
I only read Ancs post because he is so damn smart and I always read his posts.
I'm taking a break from getting involved helping others for a while.
You have a long journey in front of you.
If you don't have or can't get the books use growweedeasy.com
If you can get the books:
Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible
or
Marijuana Grower's Handbook by Ed Rosenthal
I won't debate if ffof is soil. Start a thread asking if it is soil. See if anyone else thinks it is not soil. I'd be curious if you can find others that think it is not soil.
Ever consider making your own soil from scratch?
If you make your own soil from scratch one of the ingredients is peat.
My opinion, if potassium is not getting to the plant, it is not because there is not enough potassium in the soil.
Again just my opinion.
I have used ocean forest a long time. My guess is the soil does not have a lack of potassium, might be locked out but that is likely from something you did wrong.
Most common reasons are improper watering or adding something that should not have been added.
I have grown plants in ffof with just water and had healthy plants to the end.
Another note. ffof should get nothing but water for the 1st 4 weeks.
Good Luck!