Epic 50 Seed Super Sour Diesel Pheno Hunt in my 2x4! Help Growmies!

This is WILD.
I called harley smith and he picked up and dedicate me 30 minutes of consulence I still cannot believe it!
Explained to him the situation and he told me that humics and fulvics should buffer the solution more than having it fluctuate and that I should start using 50% tap water with my RO so that the solution is more buffered and will not fluctuate as much, Looking for a starting ec of 0.2-0.4
I should also use higher dose of Aminoacids and use Enzymes just once a month to clean roots from death material and not like a preventative.
If I wanted to continue using RO he said to buy organic calmag wich is made from calcium carbonate and magnesium carbonate that will buffer the RO water like Tap.

Moral of the story,
Harley Smith is a Mothafking Top G

Quick video update

Wth is this?
Is like white not yellow, only on 2-3 plants
I think its because they still sitting a 5.4ph it could be some trace mineral lockout?

Guys I could use some opinions please,
This ph issue is been going on for too long I can see the plants are very stunted, Even with harley smith advice feeding with tap water I couldn't raise it one bit. I watered yesterday with feed at 6.9ph, runoff was 6.2 but even after just 2 hours ph was still 5.3 as always...
I am running out of ideas and scientific research.
One thing I could try today is top dressing with some more coco and Lime and water it to try and get that stabilized.

Also more plants are starting to show this last whitening signs a bit everywhere now and I am still seeing phosphorus lockout. Very scary guys I am considering giving a shot to advanced nutrients ph perfect line hopefully it can help?
PS. I just called Advance nutrients and one dude told me that I have too many castings in the medium, he couldn't really explain why that would be the issue but that was his opinion, I was certainly listenings but so many growers do a mix of coco and castings and don't have this crazy ph problems so idk. I am now looking deeply into Cation Exchange and see what can I do to mantaine a good balance
Please at this point anything even a bit of brainstorming is very welcomed!

One pheno could be a bit Albino let’s gooooooo!