First Time Grower: Potassium deficiency?

So, short intro to describe my situation, grow medium, lights and so on.
You can just skip this if you don´t want or need the details. What do I know...
I grow in a PC-cabinet, with 35w CFL 6400K over each plant.
My soil is a mix of30% cow manure, 60% peat/turf and 10% sand. I have also added about 20% perlite and vermiculite mix. The airflow is good, as I have quite many fans in my PC-cabinet and the temperature is right. Usually in the midst of 70 - 80 fahrenheit.

Over to the case:
I posted some photos here earlier as I saw that my one plant was getting some spots.
I also googled and doodled around and found out that it might have been calcium and/or magnesium defiency.
Some supported this case, others said it might be a wind burn. I have now decreased the airflow in my cabinet.
I also added some magnesium (though in a form which was to be consumed oral by humans). I should have bought epsom salt.

Anyways, as it turns out, I don´t think this was the real problem.
As i googled on i found that it most likely was potassium deficiency as the leaves were getting yellow and spotty from the bottom and up. I had some organic nutrition, consisting of living microorganisms that would create potassium amongst other things.

I added this with some watering, and I am hoping that the situation will get better.

Given this introduciton, I hope you can answer me a few questions.
1. Do you think I was right about potassium deficiency? How does it look?
2. Do you see any signs of over-watering? The leaves were hanging a bit earlier today (First photo), but have already raised themselves a bit through the day.
3. Should I cut off the yellow leaves? If so, by the stem?

I would also appreciate any general comments. The biggest plant is a Wappa from Paradise Seeds, autoflower and feminized. The smaller one is an AK-47 from Nirvana Seeds I believe, also auto and fem.

They are 24(AK-47) and 25(Wappa) days above soil.

Note: any advice or comment is appreciated. Thanks for helping out. This is my first grow ever.

i can't see a pic but maybe this link will be helpful. GL

https://www.icmag.com/ic/showthread.php?t=11688

Sorry, totally forgot the pictures.
And when I tried to edit the post, it said i needed 10 characters, which I had, in addition to the pictures. Thanks for replying, here´s the pics, check em out


Here you see the AK-47 looking a bit weak.

About 12 hours later already looking better.

Wappa not looking too good.

Already better here.


Just general photo showing the deficiency.

*bump*

....

Organic nutrition does not "create" P, or any other macro or micro nutrient. The soil mix you have made IS LOW in P&K and your going to need to "add" some. I would water with a pH balanced solution to help any possible locking out by pH of the P......And yes, Low P is your most visible problem.

I would attack your problem by adding some dolomite Lime to the soil. Then some liquid fish emulsion (that's an easy one and helps the NPK across the range) or a bone meal (be careful with that one as the P is like 15!), Jamaican/Indonesian Bat guano, or any all purpose Bird guano's and remember to follow the package directions.

You will NOT see any type of "recovery" for those effected leaves..only the problem stopping it's advance up the plant, and it will take 5-7 days for that to start. SO then if you can find a nice foliar like AGE OLD FISH and SEAWEED at 1-2 tsp per gallon of pHed water (works well for me), you will get faster results, but you still need to amend the soil with some of the nutrients above! to get the long lasting results you seek (Age Old will work for the long term too! Up to 1-2 TBL of it to 1 gallon of water and "water" with it). Your adding the bio's/zyme's already so maybe use the fert's at the low concentrations every fourth day and go up from there if need be.
http://4hydroponics.com/age-old-fish-and-seaweed

Good Luck