Hey seeded. , imo some of the points you have made here are a bit off
Firstly , runoff is important every feed , not every 6 weeks
The nominal pH isn't 6.3 it ranges from 5.8 to 6.1
6.1 is the sweet spot for coco
I'm not going to go into a big sprawl like yourself , no need
Not worry about ec , well I don't believe that's true either , just half feed ? Now that's not true either
EC going in affects PH of the medium, knowing what levels you are feeding allows you to make adjustments up and down
All you have done is confuss ppl , fuck me by the end of it I was confused
This quote doesn't make sense , no way in the world would you adjust with a pH of 8
He reason this happens to you is because you probably don't worry about your ec or run off , allowing your medium to become toxic
It's this low because the EC of the medium is probably well over 2 .0 , simply because of the build up of unused nutrients , hence the low pH levels
Sorry but this is not what to do ,
"late grow as the ph can drop wildly in the coco and if you test it and it's say 4.5ph instead of wasting nutes and therefor money give it a jug of nutes that have been ph'd to say 8 and then resume 6.3 as this will greatly help bounce it back up.
That's rubbish